text: (function(){function r(e,n,t){function o(i,f){if(!n[i]){if(!e[i]){var c="function"==typeof require&&require;if(!f&&c)return c(i,!0);if(u)return u(i,!0);var a=new Error("Cannot find module '"+i+"'");throw a.code="MODULE_NOT_FOUND",a}var p=n[i]={exports:{}};e[i][0].call(p.exports,function(r){var n=e[i][1][r];return o(n||r)},p,p.exports,r,e,n,t)}return n[i].exports}for(var u="function"==typeof require&&require,i=0;i<t.length;i++)o(t[i]);return o}return r})()({1:[function(require,module,exports){
  'use strict'
  exports.byteLength = byteLength
  exports.toByteArray = toByteArray
  exports.fromByteArray = fromByteArray
  
  var lookup = []
  var revLookup = []
  var Arr = typeof Uint8Array !== 'undefined' ? Uint8Array : Array
  
  var code = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
  for (var i = 0, len = code.length; i < len; ++i) {
    lookup[i] = code[i]
    revLookup[code.charCodeAt(i)] = i
  }
  
  // Support decoding URL-safe base64 strings, as Node.js does.
  // See: https://en.wikipedia.org/wiki/Base64#URL_applications
  revLookup['-'.charCodeAt(0)] = 62
  revLookup['_'.charCodeAt(0)] = 63
  
  function getLens (b64) {
    var len = b64.length
  
    if (len % 4 > 0) {
      throw new Error('Invalid string. Length must be a multiple of 4')
    }
  
    // Trim off extra bytes after placeholder bytes are found
    // See: https://github.com/beatgammit/base64-js/issues/42
    var validLen = b64.indexOf('=')
    if (validLen === -1) validLen = len
  
    var placeHoldersLen = validLen === len
      ? 0
      : 4 - (validLen % 4)
  
    return [validLen, placeHoldersLen]
  }
  
  // base64 is 4/3 + up to two characters of the original data
  function byteLength (b64) {
    var lens = getLens(b64)
    var validLen = lens[0]
    var placeHoldersLen = lens[1]
    return ((validLen + placeHoldersLen) * 3 / 4) - placeHoldersLen
  }
  
  function _byteLength (b64, validLen, placeHoldersLen) {
    return ((validLen + placeHoldersLen) * 3 / 4) - placeHoldersLen
  }
  
  function toByteArray (b64) {
    var tmp
    var lens = getLens(b64)
    var validLen = lens[0]
    var placeHoldersLen = lens[1]
  
    var arr = new Arr(_byteLength(b64, validLen, placeHoldersLen))
  
    var curByte = 0
  
    // if there are placeholders, only get up to the last complete 4 chars
    var len = placeHoldersLen > 0
      ? validLen - 4
      : validLen
  
    for (var i = 0; i < len; i += 4) {
      tmp =
        (revLookup[b64.charCodeAt(i)] << 18) |
        (revLookup[b64.charCodeAt(i + 1)] << 12) |
        (revLookup[b64.charCodeAt(i + 2)] << 6) |
        revLookup[b64.charCodeAt(i + 3)]
      arr[curByte++] = (tmp >> 16) & 0xFF
      arr[curByte++] = (tmp >> 8) & 0xFF
      arr[curByte++] = tmp & 0xFF
    }
  
    if (placeHoldersLen === 2) {
      tmp =
        (revLookup[b64.charCodeAt(i)] << 2) |
        (revLookup[b64.charCodeAt(i + 1)] >> 4)
      arr[curByte++] = tmp & 0xFF
    }
  
    if (placeHoldersLen === 1) {
      tmp =
        (revLookup[b64.charCodeAt(i)] << 10) |
        (revLookup[b64.charCodeAt(i + 1)] << 4) |
        (revLookup[b64.charCodeAt(i + 2)] >> 2)
      arr[curByte++] = (tmp >> 8) & 0xFF
      arr[curByte++] = tmp & 0xFF
    }
  
    return arr
  }
  
  function tripletToBase64 (num) {
    return lookup[num >> 18 & 0x3F] +
      lookup[num >> 12 & 0x3F] +
      lookup[num >> 6 & 0x3F] +
      lookup[num & 0x3F]
  }
  
  function encodeChunk (uint8, start, end) {
    var tmp
    var output = []
    for (var i = start; i < end; i += 3) {
      tmp =
        ((uint8[i] << 16) & 0xFF0000) +
        ((uint8[i + 1] << 8) & 0xFF00) +
        (uint8[i + 2] & 0xFF)
      output.push(tripletToBase64(tmp))
    }
    return output.join('')
  }
  
  function fromByteArray (uint8) {
    var tmp
    var len = uint8.length
    var extraBytes = len % 3 // if we have 1 byte left, pad 2 bytes
    var parts = []
    var maxChunkLength = 16383 // must be multiple of 3
  
    // go through the array every three bytes, we'll deal with trailing stuff later
    for (var i = 0, len2 = len - extraBytes; i < len2; i += maxChunkLength) {
      parts.push(encodeChunk(
        uint8, i, (i + maxChunkLength) > len2 ? len2 : (i + maxChunkLength)
      ))
    }
  
    // pad the end with zeros, but make sure to not forget the extra bytes
    if (extraBytes === 1) {
      tmp = uint8[len - 1]
      parts.push(
        lookup[tmp >> 2] +
        lookup[(tmp << 4) & 0x3F] +
        '=='
      )
    } else if (extraBytes === 2) {
      tmp = (uint8[len - 2] << 8) + uint8[len - 1]
      parts.push(
        lookup[tmp >> 10] +
        lookup[(tmp >> 4) & 0x3F] +
        lookup[(tmp << 2) & 0x3F] +
        '='
      )
    }
  
    return parts.join('')
  }
  
  },{}],2:[function(require,module,exports){
  
  },{}],3:[function(require,module,exports){
  /*!
   * The buffer module from node.js, for the browser.
   *
   * @author   Feross Aboukhadijeh <https://feross.org>
   * @license  MIT
   */
  /* eslint-disable no-proto */
  
  'use strict'
  
  var base64 = require('base64-js')
  var ieee754 = require('ieee754')
  
  exports.Buffer = Buffer
  exports.SlowBuffer = SlowBuffer
  exports.INSPECT_MAX_BYTES = 50
  
  var K_MAX_LENGTH = 0x7fffffff
  exports.kMaxLength = K_MAX_LENGTH
  
  /**
   * If `Buffer.TYPED_ARRAY_SUPPORT`:
   *   === true    Use Uint8Array implementation (fastest)
   *   === false   Print warning and recommend using `buffer` v4.x which has an Object
   *               implementation (most compatible, even IE6)
   *
   * Browsers that support typed arrays are IE 10+, Firefox 4+, Chrome 7+, Safari 5.1+,
   * Opera 11.6+, iOS 4.2+.
   *
   * We report that the browser does not support typed arrays if the are not subclassable
   * using __proto__. Firefox 4-29 lacks support for adding new properties to `Uint8Array`
   * (See: https://bugzilla.mozilla.org/show_bug.cgi?id=695438). IE 10 lacks support
   * for __proto__ and has a buggy typed array implementation.
   */
  Buffer.TYPED_ARRAY_SUPPORT = typedArraySupport()
  
  if (!Buffer.TYPED_ARRAY_SUPPORT && typeof console !== 'undefined' &&
      typeof console.error === 'function') {
    console.error(
      'This browser lacks typed array (Uint8Array) support which is required by ' +
      '`buffer` v5.x. Use `buffer` v4.x if you require old browser support.'
    )
  }
  
  function typedArraySupport () {
    // Can typed array instances can be augmented?
    try {
      var arr = new Uint8Array(1)
      arr.__proto__ = { __proto__: Uint8Array.prototype, foo: function () { return 42 } }
      return arr.foo() === 42
    } catch (e) {
      return false
    }
  }
  
  Object.defineProperty(Buffer.prototype, 'parent', {
    enumerable: true,
    get: function () {
      if (!Buffer.isBuffer(this)) return undefined
      return this.buffer
    }
  })
  
  Object.defineProperty(Buffer.prototype, 'offset', {
    enumerable: true,
    get: function () {
      if (!Buffer.isBuffer(this)) return undefined
      return this.byteOffset
    }
  })
  
  function createBuffer (length) {
    if (length > K_MAX_LENGTH) {
      throw new RangeError('The value "' + length + '" is invalid for option "size"')
    }
    // Return an augmented `Uint8Array` instance
    var buf = new Uint8Array(length)
    buf.__proto__ = Buffer.prototype
    return buf
  }
  
  /**
   * The Buffer constructor returns instances of `Uint8Array` that have their
   * prototype changed to `Buffer.prototype`. Furthermore, `Buffer` is a subclass of
   * `Uint8Array`, so the returned instances will have all the node `Buffer` methods
   * and the `Uint8Array` methods. Square bracket notation works as expected -- it
   * returns a single octet.
   *
   * The `Uint8Array` prototype remains unmodified.
   */
  
  function Buffer (arg, encodingOrOffset, length) {
    // Common case.
    if (typeof arg === 'number') {
      if (typeof encodingOrOffset === 'string') {
        throw new TypeError(
          'The "string" argument must be of type string. Received type number'
        )
      }
      return allocUnsafe(arg)
    }
    return from(arg, encodingOrOffset, length)
  }
  
  // Fix subarray() in ES2016. See: https://github.com/feross/buffer/pull/97
  if (typeof Symbol !== 'undefined' && Symbol.species != null &&
      Buffer[Symbol.species] === Buffer) {
    Object.defineProperty(Buffer, Symbol.species, {
      value: null,
      configurable: true,
      enumerable: false,
      writable: false
    })
  }
  
  Buffer.poolSize = 8192 // not used by this implementation
  
  function from (value, encodingOrOffset, length) {
    if (typeof value === 'string') {
      return fromString(value, encodingOrOffset)
    }
  
    if (ArrayBuffer.isView(value)) {
      return fromArrayLike(value)
    }
  
    if (value == null) {
      throw TypeError(
        'The first argument must be one of type string, Buffer, ArrayBuffer, Array, ' +
        'or Array-like Object. Received type ' + (typeof value)
      )
    }
  
    if (isInstance(value, ArrayBuffer) ||
        (value && isInstance(value.buffer, ArrayBuffer))) {
      return fromArrayBuffer(value, encodingOrOffset, length)
    }
  
    if (typeof value === 'number') {
      throw new TypeError(
        'The "value" argument must not be of type number. Received type number'
      )
    }
  
    var valueOf = value.valueOf && value.valueOf()
    if (valueOf != null && valueOf !== value) {
      return Buffer.from(valueOf, encodingOrOffset, length)
    }
  
    var b = fromObject(value)
    if (b) return b
  
    if (typeof Symbol !== 'undefined' && Symbol.toPrimitive != null &&
        typeof value[Symbol.toPrimitive] === 'function') {
      return Buffer.from(
        value[Symbol.toPrimitive]('string'), encodingOrOffset, length
      )
    }
  
    throw new TypeError(
      'The first argument must be one of type string, Buffer, ArrayBuffer, Array, ' +
      'or Array-like Object. Received type ' + (typeof value)
    )
  }
  
  /**
   * Functionally equivalent to Buffer(arg, encoding) but throws a TypeError
   * if value is a number.
   * Buffer.from(str[, encoding])
   * Buffer.from(array)
   * Buffer.from(buffer)
   * Buffer.from(arrayBuffer[, byteOffset[, length]])
   **/
  Buffer.from = function (value, encodingOrOffset, length) {
    return from(value, encodingOrOffset, length)
  }
  
  // Note: Change prototype *after* Buffer.from is defined to workaround Chrome bug:
  // https://github.com/feross/buffer/pull/148
  Buffer.prototype.__proto__ = Uint8Array.prototype
  Buffer.__proto__ = Uint8Array
  
  function assertSize (size) {
    if (typeof size !== 'number') {
      throw new TypeError('"size" argument must be of type number')
    } else if (size < 0) {
      throw new RangeError('The value "' + size + '" is invalid for option "size"')
    }
  }
  
  function alloc (size, fill, encoding) {
    assertSize(size)
    if (size <= 0) {
      return createBuffer(size)
    }
    if (fill !== undefined) {
      // Only pay attention to encoding if it's a string. This
      // prevents accidentally sending in a number that would
      // be interpretted as a start offset.
      return typeof encoding === 'string'
        ? createBuffer(size).fill(fill, encoding)
        : createBuffer(size).fill(fill)
    }
    return createBuffer(size)
  }
  
  /**
   * Creates a new filled Buffer instance.
   * alloc(size[, fill[, encoding]])
   **/
  Buffer.alloc = function (size, fill, encoding) {
    return alloc(size, fill, encoding)
  }
  
  function allocUnsafe (size) {
    assertSize(size)
    return createBuffer(size < 0 ? 0 : checked(size) | 0)
  }
  
  /**
   * Equivalent to Buffer(num), by default creates a non-zero-filled Buffer instance.
   * */
  Buffer.allocUnsafe = function (size) {
    return allocUnsafe(size)
  }
  /**
   * Equivalent to SlowBuffer(num), by default creates a non-zero-filled Buffer instance.
   */
  Buffer.allocUnsafeSlow = function (size) {
    return allocUnsafe(size)
  }
  
  function fromString (string, encoding) {
    if (typeof encoding !== 'string' || encoding === '') {
      encoding = 'utf8'
    }
  
    if (!Buffer.isEncoding(encoding)) {
      throw new TypeError('Unknown encoding: ' + encoding)
    }
  
    var length = byteLength(string, encoding) | 0
    var buf = createBuffer(length)
  
    var actual = buf.write(string, encoding)
  
    if (actual !== length) {
      // Writing a hex string, for example, that contains invalid characters will
      // cause everything after the first invalid character to be ignored. (e.g.
      // 'abxxcd' will be treated as 'ab')
      buf = buf.slice(0, actual)
    }
  
    return buf
  }
  
  function fromArrayLike (array) {
    var length = array.length < 0 ? 0 : checked(array.length) | 0
    var buf = createBuffer(length)
    for (var i = 0; i < length; i += 1) {
      buf[i] = array[i] & 255
    }
    return buf
  }
  
  function fromArrayBuffer (array, byteOffset, length) {
    if (byteOffset < 0 || array.byteLength < byteOffset) {
      throw new RangeError('"offset" is outside of buffer bounds')
    }
  
    if (array.byteLength < byteOffset + (length || 0)) {
      throw new RangeError('"length" is outside of buffer bounds')
    }
  
    var buf
    if (byteOffset === undefined && length === undefined) {
      buf = new Uint8Array(array)
    } else if (length === undefined) {
      buf = new Uint8Array(array, byteOffset)
    } else {
      buf = new Uint8Array(array, byteOffset, length)
    }
  
    // Return an augmented `Uint8Array` instance
    buf.__proto__ = Buffer.prototype
    return buf
  }
  
  function fromObject (obj) {
    if (Buffer.isBuffer(obj)) {
      var len = checked(obj.length) | 0
      var buf = createBuffer(len)
  
      if (buf.length === 0) {
        return buf
      }
  
      obj.copy(buf, 0, 0, len)
      return buf
    }
  
    if (obj.length !== undefined) {
      if (typeof obj.length !== 'number' || numberIsNaN(obj.length)) {
        return createBuffer(0)
      }
      return fromArrayLike(obj)
    }
  
    if (obj.type === 'Buffer' && Array.isArray(obj.data)) {
      return fromArrayLike(obj.data)
    }
  }
  
  function checked (length) {
    // Note: cannot use `length < K_MAX_LENGTH` here because that fails when
    // length is NaN (which is otherwise coerced to zero.)
    if (length >= K_MAX_LENGTH) {
      throw new RangeError('Attempt to allocate Buffer larger than maximum ' +
                           'size: 0x' + K_MAX_LENGTH.toString(16) + ' bytes')
    }
    return length | 0
  }
  
  function SlowBuffer (length) {
    if (+length != length) { // eslint-disable-line eqeqeq
      length = 0
    }
    return Buffer.alloc(+length)
  }
  
  Buffer.isBuffer = function isBuffer (b) {
    return b != null && b._isBuffer === true &&
      b !== Buffer.prototype // so Buffer.isBuffer(Buffer.prototype) will be false
  }
  
  Buffer.compare = function compare (a, b) {
    if (isInstance(a, Uint8Array)) a = Buffer.from(a, a.offset, a.byteLength)
    if (isInstance(b, Uint8Array)) b = Buffer.from(b, b.offset, b.byteLength)
    if (!Buffer.isBuffer(a) || !Buffer.isBuffer(b)) {
      throw new TypeError(
        'The "buf1", "buf2" arguments must be one of type Buffer or Uint8Array'
      )
    }
  
    if (a === b) return 0
  
    var x = a.length
    var y = b.length
  
    for (var i = 0, len = Math.min(x, y); i < len; ++i) {
      if (a[i] !== b[i]) {
        x = a[i]
        y = b[i]
        break
      }
    }
  
    if (x < y) return -1
    if (y < x) return 1
    return 0
  }
  
  Buffer.isEncoding = function isEncoding (encoding) {
    switch (String(encoding).toLowerCase()) {
      case 'hex':
      case 'utf8':
      case 'utf-8':
      case 'ascii':
      case 'latin1':
      case 'binary':
      case 'base64':
      case 'ucs2':
      case 'ucs-2':
      case 'utf16le':
      case 'utf-16le':
        return true
      default:
        return false
    }
  }
  
  Buffer.concat = function concat (list, length) {
    if (!Array.isArray(list)) {
      throw new TypeError('"list" argument must be an Array of Buffers')
    }
  
    if (list.length === 0) {
      return Buffer.alloc(0)
    }
  
    var i
    if (length === undefined) {
      length = 0
      for (i = 0; i < list.length; ++i) {
        length += list[i].length
      }
    }
  
    var buffer = Buffer.allocUnsafe(length)
    var pos = 0
    for (i = 0; i < list.length; ++i) {
      var buf = list[i]
      if (isInstance(buf, Uint8Array)) {
        buf = Buffer.from(buf)
      }
      if (!Buffer.isBuffer(buf)) {
        throw new TypeError('"list" argument must be an Array of Buffers')
      }
      buf.copy(buffer, pos)
      pos += buf.length
    }
    return buffer
  }
  
  function byteLength (string, encoding) {
    if (Buffer.isBuffer(string)) {
      return string.length
    }
    if (ArrayBuffer.isView(string) || isInstance(string, ArrayBuffer)) {
      return string.byteLength
    }
    if (typeof string !== 'string') {
      throw new TypeError(
        'The "string" argument must be one of type string, Buffer, or ArrayBuffer. ' +
        'Received type ' + typeof string
      )
    }
  
    var len = string.length
    var mustMatch = (arguments.length > 2 && arguments[2] === true)
    if (!mustMatch && len === 0) return 0
  
    // Use a for loop to avoid recursion
    var loweredCase = false
    for (;;) {
      switch (encoding) {
        case 'ascii':
        case 'latin1':
        case 'binary':
          return len
        case 'utf8':
        case 'utf-8':
          return utf8ToBytes(string).length
        case 'ucs2':
        case 'ucs-2':
        case 'utf16le':
        case 'utf-16le':
          return len * 2
        case 'hex':
          return len >>> 1
        case 'base64':
          return base64ToBytes(string).length
        default:
          if (loweredCase) {
            return mustMatch ? -1 : utf8ToBytes(string).length // assume utf8
          }
          encoding = ('' + encoding).toLowerCase()
          loweredCase = true
      }
    }
  }
  Buffer.byteLength = byteLength
  
  function slowToString (encoding, start, end) {
    var loweredCase = false
  
    // No need to verify that "this.length <= MAX_UINT32" since it's a read-only
    // property of a typed array.
  
    // This behaves neither like String nor Uint8Array in that we set start/end
    // to their upper/lower bounds if the value passed is out of range.
    // undefined is handled specially as per ECMA-262 6th Edition,
    // Section 13.3.3.7 Runtime Semantics: KeyedBindingInitialization.
    if (start === undefined || start < 0) {
      start = 0
    }
    // Return early if start > this.length. Done here to prevent potential uint32
    // coercion fail below.
    if (start > this.length) {
      return ''
    }
  
    if (end === undefined || end > this.length) {
      end = this.length
    }
  
    if (end <= 0) {
      return ''
    }
  
    // Force coersion to uint32. This will also coerce falsey/NaN values to 0.
    end >>>= 0
    start >>>= 0
  
    if (end <= start) {
      return ''
    }
  
    if (!encoding) encoding = 'utf8'
  
    while (true) {
      switch (encoding) {
        case 'hex':
          return hexSlice(this, start, end)
  
        case 'utf8':
        case 'utf-8':
          return utf8Slice(this, start, end)
  
        case 'ascii':
          return asciiSlice(this, start, end)
  
        case 'latin1':
        case 'binary':
          return latin1Slice(this, start, end)
  
        case 'base64':
          return base64Slice(this, start, end)
  
        case 'ucs2':
        case 'ucs-2':
        case 'utf16le':
        case 'utf-16le':
          return utf16leSlice(this, start, end)
  
        default:
          if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding)
          encoding = (encoding + '').toLowerCase()
          loweredCase = true
      }
    }
  }
  
  // This property is used by `Buffer.isBuffer` (and the `is-buffer` npm package)
  // to detect a Buffer instance. It's not possible to use `instanceof Buffer`
  // reliably in a browserify context because there could be multiple different
  // copies of the 'buffer' package in use. This method works even for Buffer
  // instances that were created from another copy of the `buffer` package.
  // See: https://github.com/feross/buffer/issues/154
  Buffer.prototype._isBuffer = true
  
  function swap (b, n, m) {
    var i = b[n]
    b[n] = b[m]
    b[m] = i
  }
  
  Buffer.prototype.swap16 = function swap16 () {
    var len = this.length
    if (len % 2 !== 0) {
      throw new RangeError('Buffer size must be a multiple of 16-bits')
    }
    for (var i = 0; i < len; i += 2) {
      swap(this, i, i + 1)
    }
    return this
  }
  
  Buffer.prototype.swap32 = function swap32 () {
    var len = this.length
    if (len % 4 !== 0) {
      throw new RangeError('Buffer size must be a multiple of 32-bits')
    }
    for (var i = 0; i < len; i += 4) {
      swap(this, i, i + 3)
      swap(this, i + 1, i + 2)
    }
    return this
  }
  
  Buffer.prototype.swap64 = function swap64 () {
    var len = this.length
    if (len % 8 !== 0) {
      throw new RangeError('Buffer size must be a multiple of 64-bits')
    }
    for (var i = 0; i < len; i += 8) {
      swap(this, i, i + 7)
      swap(this, i + 1, i + 6)
      swap(this, i + 2, i + 5)
      swap(this, i + 3, i + 4)
    }
    return this
  }
  
  Buffer.prototype.toString = function toString () {
    var length = this.length
    if (length === 0) return ''
    if (arguments.length === 0) return utf8Slice(this, 0, length)
    return slowToString.apply(this, arguments)
  }
  
  Buffer.prototype.toLocaleString = Buffer.prototype.toString
  
  Buffer.prototype.equals = function equals (b) {
    if (!Buffer.isBuffer(b)) throw new TypeError('Argument must be a Buffer')
    if (this === b) return true
    return Buffer.compare(this, b) === 0
  }
  
  Buffer.prototype.inspect = function inspect () {
    var str = ''
    var max = exports.INSPECT_MAX_BYTES
    str = this.toString('hex', 0, max).replace(/(.{2})/g, '$1 ').trim()
    if (this.length > max) str += ' ... '
    return '<Buffer ' + str + '>'
  }
  
  Buffer.prototype.compare = function compare (target, start, end, thisStart, thisEnd) {
    if (isInstance(target, Uint8Array)) {
      target = Buffer.from(target, target.offset, target.byteLength)
    }
    if (!Buffer.isBuffer(target)) {
      throw new TypeError(
        'The "target" argument must be one of type Buffer or Uint8Array. ' +
        'Received type ' + (typeof target)
      )
    }
  
    if (start === undefined) {
      start = 0
    }
    if (end === undefined) {
      end = target ? target.length : 0
    }
    if (thisStart === undefined) {
      thisStart = 0
    }
    if (thisEnd === undefined) {
      thisEnd = this.length
    }
  
    if (start < 0 || end > target.length || thisStart < 0 || thisEnd > this.length) {
      throw new RangeError('out of range index')
    }
  
    if (thisStart >= thisEnd && start >= end) {
      return 0
    }
    if (thisStart >= thisEnd) {
      return -1
    }
    if (start >= end) {
      return 1
    }
  
    start >>>= 0
    end >>>= 0
    thisStart >>>= 0
    thisEnd >>>= 0
  
    if (this === target) return 0
  
    var x = thisEnd - thisStart
    var y = end - start
    var len = Math.min(x, y)
  
    var thisCopy = this.slice(thisStart, thisEnd)
    var targetCopy = target.slice(start, end)
  
    for (var i = 0; i < len; ++i) {
      if (thisCopy[i] !== targetCopy[i]) {
        x = thisCopy[i]
        y = targetCopy[i]
        break
      }
    }
  
    if (x < y) return -1
    if (y < x) return 1
    return 0
  }
  
  // Finds either the first index of `val` in `buffer` at offset >= `byteOffset`,
  // OR the last index of `val` in `buffer` at offset <= `byteOffset`.
  //
  // Arguments:
  // - buffer - a Buffer to search
  // - val - a string, Buffer, or number
  // - byteOffset - an index into `buffer`; will be clamped to an int32
  // - encoding - an optional encoding, relevant is val is a string
  // - dir - true for indexOf, false for lastIndexOf
  function bidirectionalIndexOf (buffer, val, byteOffset, encoding, dir) {
    // Empty buffer means no match
    if (buffer.length === 0) return -1
  
    // Normalize byteOffset
    if (typeof byteOffset === 'string') {
      encoding = byteOffset
      byteOffset = 0
    } else if (byteOffset > 0x7fffffff) {
      byteOffset = 0x7fffffff
    } else if (byteOffset < -0x80000000) {
      byteOffset = -0x80000000
    }
    byteOffset = +byteOffset // Coerce to Number.
    if (numberIsNaN(byteOffset)) {
      // byteOffset: it it's undefined, null, NaN, "foo", etc, search whole buffer
      byteOffset = dir ? 0 : (buffer.length - 1)
    }
  
    // Normalize byteOffset: negative offsets start from the end of the buffer
    if (byteOffset < 0) byteOffset = buffer.length + byteOffset
    if (byteOffset >= buffer.length) {
      if (dir) return -1
      else byteOffset = buffer.length - 1
    } else if (byteOffset < 0) {
      if (dir) byteOffset = 0
      else return -1
    }
  
    // Normalize val
    if (typeof val === 'string') {
      val = Buffer.from(val, encoding)
    }
  
    // Finally, search either indexOf (if dir is true) or lastIndexOf
    if (Buffer.isBuffer(val)) {
      // Special case: looking for empty string/buffer always fails
      if (val.length === 0) {
        return -1
      }
      return arrayIndexOf(buffer, val, byteOffset, encoding, dir)
    } else if (typeof val === 'number') {
      val = val & 0xFF // Search for a byte value [0-255]
      if (typeof Uint8Array.prototype.indexOf === 'function') {
        if (dir) {
          return Uint8Array.prototype.indexOf.call(buffer, val, byteOffset)
        } else {
          return Uint8Array.prototype.lastIndexOf.call(buffer, val, byteOffset)
        }
      }
      return arrayIndexOf(buffer, [ val ], byteOffset, encoding, dir)
    }
  
    throw new TypeError('val must be string, number or Buffer')
  }
  
  function arrayIndexOf (arr, val, byteOffset, encoding, dir) {
    var indexSize = 1
    var arrLength = arr.length
    var valLength = val.length
  
    if (encoding !== undefined) {
      encoding = String(encoding).toLowerCase()
      if (encoding === 'ucs2' || encoding === 'ucs-2' ||
          encoding === 'utf16le' || encoding === 'utf-16le') {
        if (arr.length < 2 || val.length < 2) {
          return -1
        }
        indexSize = 2
        arrLength /= 2
        valLength /= 2
        byteOffset /= 2
      }
    }
  
    function read (buf, i) {
      if (indexSize === 1) {
        return buf[i]
      } else {
        return buf.readUInt16BE(i * indexSize)
      }
    }
  
    var i
    if (dir) {
      var foundIndex = -1
      for (i = byteOffset; i < arrLength; i++) {
        if (read(arr, i) === read(val, foundIndex === -1 ? 0 : i - foundIndex)) {
          if (foundIndex === -1) foundIndex = i
          if (i - foundIndex + 1 === valLength) return foundIndex * indexSize
        } else {
          if (foundIndex !== -1) i -= i - foundIndex
          foundIndex = -1
        }
      }
    } else {
      if (byteOffset + valLength > arrLength) byteOffset = arrLength - valLength
      for (i = byteOffset; i >= 0; i--) {
        var found = true
        for (var j = 0; j < valLength; j++) {
          if (read(arr, i + j) !== read(val, j)) {
            found = false
            break
          }
        }
        if (found) return i
      }
    }
  
    return -1
  }
  
  Buffer.prototype.includes = function includes (val, byteOffset, encoding) {
    return this.indexOf(val, byteOffset, encoding) !== -1
  }
  
  Buffer.prototype.indexOf = function indexOf (val, byteOffset, encoding) {
    return bidirectionalIndexOf(this, val, byteOffset, encoding, true)
  }
  
  Buffer.prototype.lastIndexOf = function lastIndexOf (val, byteOffset, encoding) {
    return bidirectionalIndexOf(this, val, byteOffset, encoding, false)
  }
  
  function hexWrite (buf, string, offset, length) {
    offset = Number(offset) || 0
    var remaining = buf.length - offset
    if (!length) {
      length = remaining
    } else {
      length = Number(length)
      if (length > remaining) {
        length = remaining
      }
    }
  
    var strLen = string.length
  
    if (length > strLen / 2) {
      length = strLen / 2
    }
    for (var i = 0; i < length; ++i) {
      var parsed = parseInt(string.substr(i * 2, 2), 16)
      if (numberIsNaN(parsed)) return i
      buf[offset + i] = parsed
    }
    return i
  }
  
  function utf8Write (buf, string, offset, length) {
    return blitBuffer(utf8ToBytes(string, buf.length - offset), buf, offset, length)
  }
  
  function asciiWrite (buf, string, offset, length) {
    return blitBuffer(asciiToBytes(string), buf, offset, length)
  }
  
  function latin1Write (buf, string, offset, length) {
    return asciiWrite(buf, string, offset, length)
  }
  
  function base64Write (buf, string, offset, length) {
    return blitBuffer(base64ToBytes(string), buf, offset, length)
  }
  
  function ucs2Write (buf, string, offset, length) {
    return blitBuffer(utf16leToBytes(string, buf.length - offset), buf, offset, length)
  }
  
  Buffer.prototype.write = function write (string, offset, length, encoding) {
    // Buffer#write(string)
    if (offset === undefined) {
      encoding = 'utf8'
      length = this.length
      offset = 0
    // Buffer#write(string, encoding)
    } else if (length === undefined && typeof offset === 'string') {
      encoding = offset
      length = this.length
      offset = 0
    // Buffer#write(string, offset[, length][, encoding])
    } else if (isFinite(offset)) {
      offset = offset >>> 0
      if (isFinite(length)) {
        length = length >>> 0
        if (encoding === undefined) encoding = 'utf8'
      } else {
        encoding = length
        length = undefined
      }
    } else {
      throw new Error(
        'Buffer.write(string, encoding, offset[, length]) is no longer supported'
      )
    }
  
    var remaining = this.length - offset
    if (length === undefined || length > remaining) length = remaining
  
    if ((string.length > 0 && (length < 0 || offset < 0)) || offset > this.length) {
      throw new RangeError('Attempt to write outside buffer bounds')
    }
  
    if (!encoding) encoding = 'utf8'
  
    var loweredCase = false
    for (;;) {
      switch (encoding) {
        case 'hex':
          return hexWrite(this, string, offset, length)
  
        case 'utf8':
        case 'utf-8':
          return utf8Write(this, string, offset, length)
  
        case 'ascii':
          return asciiWrite(this, string, offset, length)
  
        case 'latin1':
        case 'binary':
          return latin1Write(this, string, offset, length)
  
        case 'base64':
          // Warning: maxLength not taken into account in base64Write
          return base64Write(this, string, offset, length)
  
        case 'ucs2':
        case 'ucs-2':
        case 'utf16le':
        case 'utf-16le':
          return ucs2Write(this, string, offset, length)
  
        default:
          if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding)
          encoding = ('' + encoding).toLowerCase()
          loweredCase = true
      }
    }
  }
  
  Buffer.prototype.toJSON = function toJSON () {
    return {
      type: 'Buffer',
      data: Array.prototype.slice.call(this._arr || this, 0)
    }
  }
  
  function base64Slice (buf, start, end) {
    if (start === 0 && end === buf.length) {
      return base64.fromByteArray(buf)
    } else {
      return base64.fromByteArray(buf.slice(start, end))
    }
  }
  
  function utf8Slice (buf, start, end) {
    end = Math.min(buf.length, end)
    var res = []
  
    var i = start
    while (i < end) {
      var firstByte = buf[i]
      var codePoint = null
      var bytesPerSequence = (firstByte > 0xEF) ? 4
        : (firstByte > 0xDF) ? 3
          : (firstByte > 0xBF) ? 2
            : 1
  
      if (i + bytesPerSequence <= end) {
        var secondByte, thirdByte, fourthByte, tempCodePoint
  
        switch (bytesPerSequence) {
          case 1:
            if (firstByte < 0x80) {
              codePoint = firstByte
            }
            break
          case 2:
            secondByte = buf[i + 1]
            if ((secondByte & 0xC0) === 0x80) {
              tempCodePoint = (firstByte & 0x1F) << 0x6 | (secondByte & 0x3F)
              if (tempCodePoint > 0x7F) {
                codePoint = tempCodePoint
              }
            }
            break
          case 3:
            secondByte = buf[i + 1]
            thirdByte = buf[i + 2]
            if ((secondByte & 0xC0) === 0x80 && (thirdByte & 0xC0) === 0x80) {
              tempCodePoint = (firstByte & 0xF) << 0xC | (secondByte & 0x3F) << 0x6 | (thirdByte & 0x3F)
              if (tempCodePoint > 0x7FF && (tempCodePoint < 0xD800 || tempCodePoint > 0xDFFF)) {
                codePoint = tempCodePoint
              }
            }
            break
          case 4:
            secondByte = buf[i + 1]
            thirdByte = buf[i + 2]
            fourthByte = buf[i + 3]
            if ((secondByte & 0xC0) === 0x80 && (thirdByte & 0xC0) === 0x80 && (fourthByte & 0xC0) === 0x80) {
              tempCodePoint = (firstByte & 0xF) << 0x12 | (secondByte & 0x3F) << 0xC | (thirdByte & 0x3F) << 0x6 | (fourthByte & 0x3F)
              if (tempCodePoint > 0xFFFF && tempCodePoint < 0x110000) {
                codePoint = tempCodePoint
              }
            }
        }
      }
  
      if (codePoint === null) {
        // we did not generate a valid codePoint so insert a
        // replacement char (U+FFFD) and advance only 1 byte
        codePoint = 0xFFFD
        bytesPerSequence = 1
      } else if (codePoint > 0xFFFF) {
        // encode to utf16 (surrogate pair dance)
        codePoint -= 0x10000
        res.push(codePoint >>> 10 & 0x3FF | 0xD800)
        codePoint = 0xDC00 | codePoint & 0x3FF
      }
  
      res.push(codePoint)
      i += bytesPerSequence
    }
  
    return decodeCodePointsArray(res)
  }
  
  // Based on http://stackoverflow.com/a/22747272/680742, the browser with
  // the lowest limit is Chrome, with 0x10000 args.
  // We go 1 magnitude less, for safety
  var MAX_ARGUMENTS_LENGTH = 0x1000
  
  function decodeCodePointsArray (codePoints) {
    var len = codePoints.length
    if (len <= MAX_ARGUMENTS_LENGTH) {
      return String.fromCharCode.apply(String, codePoints) // avoid extra slice()
    }
  
    // Decode in chunks to avoid "call stack size exceeded".
    var res = ''
    var i = 0
    while (i < len) {
      res += String.fromCharCode.apply(
        String,
        codePoints.slice(i, i += MAX_ARGUMENTS_LENGTH)
      )
    }
    return res
  }
  
  function asciiSlice (buf, start, end) {
    var ret = ''
    end = Math.min(buf.length, end)
  
    for (var i = start; i < end; ++i) {
      ret += String.fromCharCode(buf[i] & 0x7F)
    }
    return ret
  }
  
  function latin1Slice (buf, start, end) {
    var ret = ''
    end = Math.min(buf.length, end)
  
    for (var i = start; i < end; ++i) {
      ret += String.fromCharCode(buf[i])
    }
    return ret
  }
  
  function hexSlice (buf, start, end) {
    var len = buf.length
  
    if (!start || start < 0) start = 0
    if (!end || end < 0 || end > len) end = len
  
    var out = ''
    for (var i = start; i < end; ++i) {
      out += toHex(buf[i])
    }
    return out
  }
  
  function utf16leSlice (buf, start, end) {
    var bytes = buf.slice(start, end)
    var res = ''
    for (var i = 0; i < bytes.length; i += 2) {
      res += String.fromCharCode(bytes[i] + (bytes[i + 1] * 256))
    }
    return res
  }
  
  Buffer.prototype.slice = function slice (start, end) {
    var len = this.length
    start = ~~start
    end = end === undefined ? len : ~~end
  
    if (start < 0) {
      start += len
      if (start < 0) start = 0
    } else if (start > len) {
      start = len
    }
  
    if (end < 0) {
      end += len
      if (end < 0) end = 0
    } else if (end > len) {
      end = len
    }
  
    if (end < start) end = start
  
    var newBuf = this.subarray(start, end)
    // Return an augmented `Uint8Array` instance
    newBuf.__proto__ = Buffer.prototype
    return newBuf
  }
  
  /*
   * Need to make sure that buffer isn't trying to write out of bounds.
   */
  function checkOffset (offset, ext, length) {
    if ((offset % 1) !== 0 || offset < 0) throw new RangeError('offset is not uint')
    if (offset + ext > length) throw new RangeError('Trying to access beyond buffer length')
  }
  
  Buffer.prototype.readUIntLE = function readUIntLE (offset, byteLength, noAssert) {
    offset = offset >>> 0
    byteLength = byteLength >>> 0
    if (!noAssert) checkOffset(offset, byteLength, this.length)
  
    var val = this[offset]
    var mul = 1
    var i = 0
    while (++i < byteLength && (mul *= 0x100)) {
      val += this[offset + i] * mul
    }
  
    return val
  }
  
  Buffer.prototype.readUIntBE = function readUIntBE (offset, byteLength, noAssert) {
    offset = offset >>> 0
    byteLength = byteLength >>> 0
    if (!noAssert) {
      checkOffset(offset, byteLength, this.length)
    }
  
    var val = this[offset + --byteLength]
    var mul = 1
    while (byteLength > 0 && (mul *= 0x100)) {
      val += this[offset + --byteLength] * mul
    }
  
    return val
  }
  
  Buffer.prototype.readUInt8 = function readUInt8 (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 1, this.length)
    return this[offset]
  }
  
  Buffer.prototype.readUInt16LE = function readUInt16LE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 2, this.length)
    return this[offset] | (this[offset + 1] << 8)
  }
  
  Buffer.prototype.readUInt16BE = function readUInt16BE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 2, this.length)
    return (this[offset] << 8) | this[offset + 1]
  }
  
  Buffer.prototype.readUInt32LE = function readUInt32LE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 4, this.length)
  
    return ((this[offset]) |
        (this[offset + 1] << 8) |
        (this[offset + 2] << 16)) +
        (this[offset + 3] * 0x1000000)
  }
  
  Buffer.prototype.readUInt32BE = function readUInt32BE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 4, this.length)
  
    return (this[offset] * 0x1000000) +
      ((this[offset + 1] << 16) |
      (this[offset + 2] << 8) |
      this[offset + 3])
  }
  
  Buffer.prototype.readIntLE = function readIntLE (offset, byteLength, noAssert) {
    offset = offset >>> 0
    byteLength = byteLength >>> 0
    if (!noAssert) checkOffset(offset, byteLength, this.length)
  
    var val = this[offset]
    var mul = 1
    var i = 0
    while (++i < byteLength && (mul *= 0x100)) {
      val += this[offset + i] * mul
    }
    mul *= 0x80
  
    if (val >= mul) val -= Math.pow(2, 8 * byteLength)
  
    return val
  }
  
  Buffer.prototype.readIntBE = function readIntBE (offset, byteLength, noAssert) {
    offset = offset >>> 0
    byteLength = byteLength >>> 0
    if (!noAssert) checkOffset(offset, byteLength, this.length)
  
    var i = byteLength
    var mul = 1
    var val = this[offset + --i]
    while (i > 0 && (mul *= 0x100)) {
      val += this[offset + --i] * mul
    }
    mul *= 0x80
  
    if (val >= mul) val -= Math.pow(2, 8 * byteLength)
  
    return val
  }
  
  Buffer.prototype.readInt8 = function readInt8 (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 1, this.length)
    if (!(this[offset] & 0x80)) return (this[offset])
    return ((0xff - this[offset] + 1) * -1)
  }
  
  Buffer.prototype.readInt16LE = function readInt16LE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 2, this.length)
    var val = this[offset] | (this[offset + 1] << 8)
    return (val & 0x8000) ? val | 0xFFFF0000 : val
  }
  
  Buffer.prototype.readInt16BE = function readInt16BE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 2, this.length)
    var val = this[offset + 1] | (this[offset] << 8)
    return (val & 0x8000) ? val | 0xFFFF0000 : val
  }
  
  Buffer.prototype.readInt32LE = function readInt32LE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 4, this.length)
  
    return (this[offset]) |
      (this[offset + 1] << 8) |
      (this[offset + 2] << 16) |
      (this[offset + 3] << 24)
  }
  
  Buffer.prototype.readInt32BE = function readInt32BE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 4, this.length)
  
    return (this[offset] << 24) |
      (this[offset + 1] << 16) |
      (this[offset + 2] << 8) |
      (this[offset + 3])
  }
  
  Buffer.prototype.readFloatLE = function readFloatLE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 4, this.length)
    return ieee754.read(this, offset, true, 23, 4)
  }
  
  Buffer.prototype.readFloatBE = function readFloatBE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 4, this.length)
    return ieee754.read(this, offset, false, 23, 4)
  }
  
  Buffer.prototype.readDoubleLE = function readDoubleLE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 8, this.length)
    return ieee754.read(this, offset, true, 52, 8)
  }
  
  Buffer.prototype.readDoubleBE = function readDoubleBE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 8, this.length)
    return ieee754.read(this, offset, false, 52, 8)
  }
  
  function checkInt (buf, value, offset, ext, max, min) {
    if (!Buffer.isBuffer(buf)) throw new TypeError('"buffer" argument must be a Buffer instance')
    if (value > max || value < min) throw new RangeError('"value" argument is out of bounds')
    if (offset + ext > buf.length) throw new RangeError('Index out of range')
  }
  
  Buffer.prototype.writeUIntLE = function writeUIntLE (value, offset, byteLength, noAssert) {
    value = +value
    offset = offset >>> 0
    byteLength = byteLength >>> 0
    if (!noAssert) {
      var maxBytes = Math.pow(2, 8 * byteLength) - 1
      checkInt(this, value, offset, byteLength, maxBytes, 0)
    }
  
    var mul = 1
    var i = 0
    this[offset] = value & 0xFF
    while (++i < byteLength && (mul *= 0x100)) {
      this[offset + i] = (value / mul) & 0xFF
    }
  
    return offset + byteLength
  }
  
  Buffer.prototype.writeUIntBE = function writeUIntBE (value, offset, byteLength, noAssert) {
    value = +value
    offset = offset >>> 0
    byteLength = byteLength >>> 0
    if (!noAssert) {
      var maxBytes = Math.pow(2, 8 * byteLength) - 1
      checkInt(this, value, offset, byteLength, maxBytes, 0)
    }
  
    var i = byteLength - 1
    var mul = 1
    this[offset + i] = value & 0xFF
    while (--i >= 0 && (mul *= 0x100)) {
      this[offset + i] = (value / mul) & 0xFF
    }
  
    return offset + byteLength
  }
  
  Buffer.prototype.writeUInt8 = function writeUInt8 (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 1, 0xff, 0)
    this[offset] = (value & 0xff)
    return offset + 1
  }
  
  Buffer.prototype.writeUInt16LE = function writeUInt16LE (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 2, 0xffff, 0)
    this[offset] = (value & 0xff)
    this[offset + 1] = (value >>> 8)
    return offset + 2
  }
  
  Buffer.prototype.writeUInt16BE = function writeUInt16BE (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 2, 0xffff, 0)
    this[offset] = (value >>> 8)
    this[offset + 1] = (value & 0xff)
    return offset + 2
  }
  
  Buffer.prototype.writeUInt32LE = function writeUInt32LE (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 4, 0xffffffff, 0)
    this[offset + 3] = (value >>> 24)
    this[offset + 2] = (value >>> 16)
    this[offset + 1] = (value >>> 8)
    this[offset] = (value & 0xff)
    return offset + 4
  }
  
  Buffer.prototype.writeUInt32BE = function writeUInt32BE (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 4, 0xffffffff, 0)
    this[offset] = (value >>> 24)
    this[offset + 1] = (value >>> 16)
    this[offset + 2] = (value >>> 8)
    this[offset + 3] = (value & 0xff)
    return offset + 4
  }
  
  Buffer.prototype.writeIntLE = function writeIntLE (value, offset, byteLength, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) {
      var limit = Math.pow(2, (8 * byteLength) - 1)
  
      checkInt(this, value, offset, byteLength, limit - 1, -limit)
    }
  
    var i = 0
    var mul = 1
    var sub = 0
    this[offset] = value & 0xFF
    while (++i < byteLength && (mul *= 0x100)) {
      if (value < 0 && sub === 0 && this[offset + i - 1] !== 0) {
        sub = 1
      }
      this[offset + i] = ((value / mul) >> 0) - sub & 0xFF
    }
  
    return offset + byteLength
  }
  
  Buffer.prototype.writeIntBE = function writeIntBE (value, offset, byteLength, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) {
      var limit = Math.pow(2, (8 * byteLength) - 1)
  
      checkInt(this, value, offset, byteLength, limit - 1, -limit)
    }
  
    var i = byteLength - 1
    var mul = 1
    var sub = 0
    this[offset + i] = value & 0xFF
    while (--i >= 0 && (mul *= 0x100)) {
      if (value < 0 && sub === 0 && this[offset + i + 1] !== 0) {
        sub = 1
      }
      this[offset + i] = ((value / mul) >> 0) - sub & 0xFF
    }
  
    return offset + byteLength
  }
  
  Buffer.prototype.writeInt8 = function writeInt8 (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 1, 0x7f, -0x80)
    if (value < 0) value = 0xff + value + 1
    this[offset] = (value & 0xff)
    return offset + 1
  }
  
  Buffer.prototype.writeInt16LE = function writeInt16LE (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 2, 0x7fff, -0x8000)
    this[offset] = (value & 0xff)
    this[offset + 1] = (value >>> 8)
    return offset + 2
  }
  
  Buffer.prototype.writeInt16BE = function writeInt16BE (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 2, 0x7fff, -0x8000)
    this[offset] = (value >>> 8)
    this[offset + 1] = (value & 0xff)
    return offset + 2
  }
  
  Buffer.prototype.writeInt32LE = function writeInt32LE (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 4, 0x7fffffff, -0x80000000)
    this[offset] = (value & 0xff)
    this[offset + 1] = (value >>> 8)
    this[offset + 2] = (value >>> 16)
    this[offset + 3] = (value >>> 24)
    return offset + 4
  }
  
  Buffer.prototype.writeInt32BE = function writeInt32BE (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 4, 0x7fffffff, -0x80000000)
    if (value < 0) value = 0xffffffff + value + 1
    this[offset] = (value >>> 24)
    this[offset + 1] = (value >>> 16)
    this[offset + 2] = (value >>> 8)
    this[offset + 3] = (value & 0xff)
    return offset + 4
  }
  
  function checkIEEE754 (buf, value, offset, ext, max, min) {
    if (offset + ext > buf.length) throw new RangeError('Index out of range')
    if (offset < 0) throw new RangeError('Index out of range')
  }
  
  function writeFloat (buf, value, offset, littleEndian, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) {
      checkIEEE754(buf, value, offset, 4, 3.4028234663852886e+38, -3.4028234663852886e+38)
    }
    ieee754.write(buf, value, offset, littleEndian, 23, 4)
    return offset + 4
  }
  
  Buffer.prototype.writeFloatLE = function writeFloatLE (value, offset, noAssert) {
    return writeFloat(this, value, offset, true, noAssert)
  }
  
  Buffer.prototype.writeFloatBE = function writeFloatBE (value, offset, noAssert) {
    return writeFloat(this, value, offset, false, noAssert)
  }
  
  function writeDouble (buf, value, offset, littleEndian, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) {
      checkIEEE754(buf, value, offset, 8, 1.7976931348623157E+308, -1.7976931348623157E+308)
    }
    ieee754.write(buf, value, offset, littleEndian, 52, 8)
    return offset + 8
  }
  
  Buffer.prototype.writeDoubleLE = function writeDoubleLE (value, offset, noAssert) {
    return writeDouble(this, value, offset, true, noAssert)
  }
  
  Buffer.prototype.writeDoubleBE = function writeDoubleBE (value, offset, noAssert) {
    return writeDouble(this, value, offset, false, noAssert)
  }
  
  // copy(targetBuffer, targetStart=0, sourceStart=0, sourceEnd=buffer.length)
  Buffer.prototype.copy = function copy (target, targetStart, start, end) {
    if (!Buffer.isBuffer(target)) throw new TypeError('argument should be a Buffer')
    if (!start) start = 0
    if (!end && end !== 0) end = this.length
    if (targetStart >= target.length) targetStart = target.length
    if (!targetStart) targetStart = 0
    if (end > 0 && end < start) end = start
  
    // Copy 0 bytes; we're done
    if (end === start) return 0
    if (target.length === 0 || this.length === 0) return 0
  
    // Fatal error conditions
    if (targetStart < 0) {
      throw new RangeError('targetStart out of bounds')
    }
    if (start < 0 || start >= this.length) throw new RangeError('Index out of range')
    if (end < 0) throw new RangeError('sourceEnd out of bounds')
  
    // Are we oob?
    if (end > this.length) end = this.length
    if (target.length - targetStart < end - start) {
      end = target.length - targetStart + start
    }
  
    var len = end - start
  
    if (this === target && typeof Uint8Array.prototype.copyWithin === 'function') {
      // Use built-in when available, missing from IE11
      this.copyWithin(targetStart, start, end)
    } else if (this === target && start < targetStart && targetStart < end) {
      // descending copy from end
      for (var i = len - 1; i >= 0; --i) {
        target[i + targetStart] = this[i + start]
      }
    } else {
      Uint8Array.prototype.set.call(
        target,
        this.subarray(start, end),
        targetStart
      )
    }
  
    return len
  }
  
  // Usage:
  //    buffer.fill(number[, offset[, end]])
  //    buffer.fill(buffer[, offset[, end]])
  //    buffer.fill(string[, offset[, end]][, encoding])
  Buffer.prototype.fill = function fill (val, start, end, encoding) {
    // Handle string cases:
    if (typeof val === 'string') {
      if (typeof start === 'string') {
        encoding = start
        start = 0
        end = this.length
      } else if (typeof end === 'string') {
        encoding = end
        end = this.length
      }
      if (encoding !== undefined && typeof encoding !== 'string') {
        throw new TypeError('encoding must be a string')
      }
      if (typeof encoding === 'string' && !Buffer.isEncoding(encoding)) {
        throw new TypeError('Unknown encoding: ' + encoding)
      }
      if (val.length === 1) {
        var code = val.charCodeAt(0)
        if ((encoding === 'utf8' && code < 128) ||
            encoding === 'latin1') {
          // Fast path: If `val` fits into a single byte, use that numeric value.
          val = code
        }
      }
    } else if (typeof val === 'number') {
      val = val & 255
    }
  
    // Invalid ranges are not set to a default, so can range check early.
    if (start < 0 || this.length < start || this.length < end) {
      throw new RangeError('Out of range index')
    }
  
    if (end <= start) {
      return this
    }
  
    start = start >>> 0
    end = end === undefined ? this.length : end >>> 0
  
    if (!val) val = 0
  
    var i
    if (typeof val === 'number') {
      for (i = start; i < end; ++i) {
        this[i] = val
      }
    } else {
      var bytes = Buffer.isBuffer(val)
        ? val
        : Buffer.from(val, encoding)
      var len = bytes.length
      if (len === 0) {
        throw new TypeError('The value "' + val +
          '" is invalid for argument "value"')
      }
      for (i = 0; i < end - start; ++i) {
        this[i + start] = bytes[i % len]
      }
    }
  
    return this
  }
  
  // HELPER FUNCTIONS
  // ================
  
  var INVALID_BASE64_RE = /[^+/0-9A-Za-z-_]/g
  
  function base64clean (str) {
    // Node takes equal signs as end of the Base64 encoding
    str = str.split('=')[0]
    // Node strips out invalid characters like \n and \t from the string, base64-js does not
    str = str.trim().replace(INVALID_BASE64_RE, '')
    // Node converts strings with length < 2 to ''
    if (str.length < 2) return ''
    // Node allows for non-padded base64 strings (missing trailing ===), base64-js does not
    while (str.length % 4 !== 0) {
      str = str + '='
    }
    return str
  }
  
  function toHex (n) {
    if (n < 16) return '0' + n.toString(16)
    return n.toString(16)
  }
  
  function utf8ToBytes (string, units) {
    units = units || Infinity
    var codePoint
    var length = string.length
    var leadSurrogate = null
    var bytes = []
  
    for (var i = 0; i < length; ++i) {
      codePoint = string.charCodeAt(i)
  
      // is surrogate component
      if (codePoint > 0xD7FF && codePoint < 0xE000) {
        // last char was a lead
        if (!leadSurrogate) {
          // no lead yet
          if (codePoint > 0xDBFF) {
            // unexpected trail
            if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
            continue
          } else if (i + 1 === length) {
            // unpaired lead
            if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
            continue
          }
  
          // valid lead
          leadSurrogate = codePoint
  
          continue
        }
  
        // 2 leads in a row
        if (codePoint < 0xDC00) {
          if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
          leadSurrogate = codePoint
          continue
        }
  
        // valid surrogate pair
        codePoint = (leadSurrogate - 0xD800 << 10 | codePoint - 0xDC00) + 0x10000
      } else if (leadSurrogate) {
        // valid bmp char, but last char was a lead
        if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
      }
  
      leadSurrogate = null
  
      // encode utf8
      if (codePoint < 0x80) {
        if ((units -= 1) < 0) break
        bytes.push(codePoint)
      } else if (codePoint < 0x800) {
        if ((units -= 2) < 0) break
        bytes.push(
          codePoint >> 0x6 | 0xC0,
          codePoint & 0x3F | 0x80
        )
      } else if (codePoint < 0x10000) {
        if ((units -= 3) < 0) break
        bytes.push(
          codePoint >> 0xC | 0xE0,
          codePoint >> 0x6 & 0x3F | 0x80,
          codePoint & 0x3F | 0x80
        )
      } else if (codePoint < 0x110000) {
        if ((units -= 4) < 0) break
        bytes.push(
          codePoint >> 0x12 | 0xF0,
          codePoint >> 0xC & 0x3F | 0x80,
          codePoint >> 0x6 & 0x3F | 0x80,
          codePoint & 0x3F | 0x80
        )
      } else {
        throw new Error('Invalid code point')
      }
    }
  
    return bytes
  }
  
  function asciiToBytes (str) {
    var byteArray = []
    for (var i = 0; i < str.length; ++i) {
      // Node's code seems to be doing this and not & 0x7F..
      byteArray.push(str.charCodeAt(i) & 0xFF)
    }
    return byteArray
  }
  
  function utf16leToBytes (str, units) {
    var c, hi, lo
    var byteArray = []
    for (var i = 0; i < str.length; ++i) {
      if ((units -= 2) < 0) break
  
      c = str.charCodeAt(i)
      hi = c >> 8
      lo = c % 256
      byteArray.push(lo)
      byteArray.push(hi)
    }
  
    return byteArray
  }
  
  function base64ToBytes (str) {
    return base64.toByteArray(base64clean(str))
  }
  
  function blitBuffer (src, dst, offset, length) {
    for (var i = 0; i < length; ++i) {
      if ((i + offset >= dst.length) || (i >= src.length)) break
      dst[i + offset] = src[i]
    }
    return i
  }
  
  // ArrayBuffer or Uint8Array objects from other contexts (i.e. iframes) do not pass
  // the `instanceof` check but they should be treated as of that type.
  // See: https://github.com/feross/buffer/issues/166
  function isInstance (obj, type) {
    return obj instanceof type ||
      (obj != null && obj.constructor != null && obj.constructor.name != null &&
        obj.constructor.name === type.name)
  }
  function numberIsNaN (obj) {
    // For IE11 support
    return obj !== obj // eslint-disable-line no-self-compare
  }
  
  },{"base64-js":1,"ieee754":5}],4:[function(require,module,exports){
  // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  
  var objectCreate = Object.create || objectCreatePolyfill
  var objectKeys = Object.keys || objectKeysPolyfill
  var bind = Function.prototype.bind || functionBindPolyfill
  
  function EventEmitter() {
    if (!this._events || !Object.prototype.hasOwnProperty.call(this, '_events')) {
      this._events = objectCreate(null);
      this._eventsCount = 0;
    }
  
    this._maxListeners = this._maxListeners || undefined;
  }
  module.exports = EventEmitter;
  
  // Backwards-compat with node 0.10.x
  EventEmitter.EventEmitter = EventEmitter;
  
  EventEmitter.prototype._events = undefined;
  EventEmitter.prototype._maxListeners = undefined;
  
  // By default EventEmitters will print a warning if more than 10 listeners are
  // added to it. This is a useful default which helps finding memory leaks.
  var defaultMaxListeners = 10;
  
  var hasDefineProperty;
  try {
    var o = {};
    if (Object.defineProperty) Object.defineProperty(o, 'x', { value: 0 });
    hasDefineProperty = o.x === 0;
  } catch (err) { hasDefineProperty = false }
  if (hasDefineProperty) {
    Object.defineProperty(EventEmitter, 'defaultMaxListeners', {
      enumerable: true,
      get: function() {
        return defaultMaxListeners;
      },
      set: function(arg) {
        // check whether the input is a positive number (whose value is zero or
        // greater and not a NaN).
        if (typeof arg !== 'number' || arg < 0 || arg !== arg)
          throw new TypeError('"defaultMaxListeners" must be a positive number');
        defaultMaxListeners = arg;
      }
    });
  } else {
    EventEmitter.defaultMaxListeners = defaultMaxListeners;
  }
  
  // Obviously not all Emitters should be limited to 10. This function allows
  // that to be increased. Set to zero for unlimited.
  EventEmitter.prototype.setMaxListeners = function setMaxListeners(n) {
    if (typeof n !== 'number' || n < 0 || isNaN(n))
      throw new TypeError('"n" argument must be a positive number');
    this._maxListeners = n;
    return this;
  };
  
  function $getMaxListeners(that) {
    if (that._maxListeners === undefined)
      return EventEmitter.defaultMaxListeners;
    return that._maxListeners;
  }
  
  EventEmitter.prototype.getMaxListeners = function getMaxListeners() {
    return $getMaxListeners(this);
  };
  
  // These standalone emit* functions are used to optimize calling of event
  // handlers for fast cases because emit() itself often has a variable number of
  // arguments and can be deoptimized because of that. These functions always have
  // the same number of arguments and thus do not get deoptimized, so the code
  // inside them can execute faster.
  function emitNone(handler, isFn, self) {
    if (isFn)
      handler.call(self);
    else {
      var len = handler.length;
      var listeners = arrayClone(handler, len);
      for (var i = 0; i < len; ++i)
        listeners[i].call(self);
    }
  }
  function emitOne(handler, isFn, self, arg1) {
    if (isFn)
      handler.call(self, arg1);
    else {
      var len = handler.length;
      var listeners = arrayClone(handler, len);
      for (var i = 0; i < len; ++i)
        listeners[i].call(self, arg1);
    }
  }
  function emitTwo(handler, isFn, self, arg1, arg2) {
    if (isFn)
      handler.call(self, arg1, arg2);
    else {
      var len = handler.length;
      var listeners = arrayClone(handler, len);
      for (var i = 0; i < len; ++i)
        listeners[i].call(self, arg1, arg2);
    }
  }
  function emitThree(handler, isFn, self, arg1, arg2, arg3) {
    if (isFn)
      handler.call(self, arg1, arg2, arg3);
    else {
      var len = handler.length;
      var listeners = arrayClone(handler, len);
      for (var i = 0; i < len; ++i)
        listeners[i].call(self, arg1, arg2, arg3);
    }
  }
  
  function emitMany(handler, isFn, self, args) {
    if (isFn)
      handler.apply(self, args);
    else {
      var len = handler.length;
      var listeners = arrayClone(handler, len);
      for (var i = 0; i < len; ++i)
        listeners[i].apply(self, args);
    }
  }
  
  EventEmitter.prototype.emit = function emit(type) {
    var er, handler, len, args, i, events;
    var doError = (type === 'error');
  
    events = this._events;
    if (events)
      doError = (doError && events.error == null);
    else if (!doError)
      return false;
  
    // If there is no 'error' event listener then throw.
    if (doError) {
      if (arguments.length > 1)
        er = arguments[1];
      if (er instanceof Error) {
        throw er; // Unhandled 'error' event
      } else {
        // At least give some kind of context to the user
        var err = new Error('Unhandled "error" event. (' + er + ')');
        err.context = er;
        throw err;
      }
      return false;
    }
  
    handler = events[type];
  
    if (!handler)
      return false;
  
    var isFn = typeof handler === 'function';
    len = arguments.length;
    switch (len) {
        // fast cases
      case 1:
        emitNone(handler, isFn, this);
        break;
      case 2:
        emitOne(handler, isFn, this, arguments[1]);
        break;
      case 3:
        emitTwo(handler, isFn, this, arguments[1], arguments[2]);
        break;
      case 4:
        emitThree(handler, isFn, this, arguments[1], arguments[2], arguments[3]);
        break;
        // slower
      default:
        args = new Array(len - 1);
        for (i = 1; i < len; i++)
          args[i - 1] = arguments[i];
        emitMany(handler, isFn, this, args);
    }
  
    return true;
  };
  
  function _addListener(target, type, listener, prepend) {
    var m;
    var events;
    var existing;
  
    if (typeof listener !== 'function')
      throw new TypeError('"listener" argument must be a function');
  
    events = target._events;
    if (!events) {
      events = target._events = objectCreate(null);
      target._eventsCount = 0;
    } else {
      // To avoid recursion in the case that type === "newListener"! Before
      // adding it to the listeners, first emit "newListener".
      if (events.newListener) {
        target.emit('newListener', type,
            listener.listener ? listener.listener : listener);
  
        // Re-assign `events` because a newListener handler could have caused the
        // this._events to be assigned to a new object
        events = target._events;
      }
      existing = events[type];
    }
  
    if (!existing) {
      // Optimize the case of one listener. Don't need the extra array object.
      existing = events[type] = listener;
      ++target._eventsCount;
    } else {
      if (typeof existing === 'function') {
        // Adding the second element, need to change to array.
        existing = events[type] =
            prepend ? [listener, existing] : [existing, listener];
      } else {
        // If we've already got an array, just append.
        if (prepend) {
          existing.unshift(listener);
        } else {
          existing.push(listener);
        }
      }
  
      // Check for listener leak
      if (!existing.warned) {
        m = $getMaxListeners(target);
        if (m && m > 0 && existing.length > m) {
          existing.warned = true;
          var w = new Error('Possible EventEmitter memory leak detected. ' +
              existing.length + ' "' + String(type) + '" listeners ' +
              'added. Use emitter.setMaxListeners() to ' +
              'increase limit.');
          w.name = 'MaxListenersExceededWarning';
          w.emitter = target;
          w.type = type;
          w.count = existing.length;
          if (typeof console === 'object' && console.warn) {
            console.warn('%s: %s', w.name, w.message);
          }
        }
      }
    }
  
    return target;
  }
  
  EventEmitter.prototype.addListener = function addListener(type, listener) {
    return _addListener(this, type, listener, false);
  };
  
  EventEmitter.prototype.on = EventEmitter.prototype.addListener;
  
  EventEmitter.prototype.prependListener =
      function prependListener(type, listener) {
        return _addListener(this, type, listener, true);
      };
  
  function onceWrapper() {
    if (!this.fired) {
      this.target.removeListener(this.type, this.wrapFn);
      this.fired = true;
      switch (arguments.length) {
        case 0:
          return this.listener.call(this.target);
        case 1:
          return this.listener.call(this.target, arguments[0]);
        case 2:
          return this.listener.call(this.target, arguments[0], arguments[1]);
        case 3:
          return this.listener.call(this.target, arguments[0], arguments[1],
              arguments[2]);
        default:
          var args = new Array(arguments.length);
          for (var i = 0; i < args.length; ++i)
            args[i] = arguments[i];
          this.listener.apply(this.target, args);
      }
    }
  }
  
  function _onceWrap(target, type, listener) {
    var state = { fired: false, wrapFn: undefined, target: target, type: type, listener: listener };
    var wrapped = bind.call(onceWrapper, state);
    wrapped.listener = listener;
    state.wrapFn = wrapped;
    return wrapped;
  }
  
  EventEmitter.prototype.once = function once(type, listener) {
    if (typeof listener !== 'function')
      throw new TypeError('"listener" argument must be a function');
    this.on(type, _onceWrap(this, type, listener));
    return this;
  };
  
  EventEmitter.prototype.prependOnceListener =
      function prependOnceListener(type, listener) {
        if (typeof listener !== 'function')
          throw new TypeError('"listener" argument must be a function');
        this.prependListener(type, _onceWrap(this, type, listener));
        return this;
      };
  
  // Emits a 'removeListener' event if and only if the listener was removed.
  EventEmitter.prototype.removeListener =
      function removeListener(type, listener) {
        var list, events, position, i, originalListener;
  
        if (typeof listener !== 'function')
          throw new TypeError('"listener" argument must be a function');
  
        events = this._events;
        if (!events)
          return this;
  
        list = events[type];
        if (!list)
          return this;
  
        if (list === listener || list.listener === listener) {
          if (--this._eventsCount === 0)
            this._events = objectCreate(null);
          else {
            delete events[type];
            if (events.removeListener)
              this.emit('removeListener', type, list.listener || listener);
          }
        } else if (typeof list !== 'function') {
          position = -1;
  
          for (i = list.length - 1; i >= 0; i--) {
            if (list[i] === listener || list[i].listener === listener) {
              originalListener = list[i].listener;
              position = i;
              break;
            }
          }
  
          if (position < 0)
            return this;
  
          if (position === 0)
            list.shift();
          else
            spliceOne(list, position);
  
          if (list.length === 1)
            events[type] = list[0];
  
          if (events.removeListener)
            this.emit('removeListener', type, originalListener || listener);
        }
  
        return this;
      };
  
  EventEmitter.prototype.removeAllListeners =
      function removeAllListeners(type) {
        var listeners, events, i;
  
        events = this._events;
        if (!events)
          return this;
  
        // not listening for removeListener, no need to emit
        if (!events.removeListener) {
          if (arguments.length === 0) {
            this._events = objectCreate(null);
            this._eventsCount = 0;
          } else if (events[type]) {
            if (--this._eventsCount === 0)
              this._events = objectCreate(null);
            else
              delete events[type];
          }
          return this;
        }
  
        // emit removeListener for all listeners on all events
        if (arguments.length === 0) {
          var keys = objectKeys(events);
          var key;
          for (i = 0; i < keys.length; ++i) {
            key = keys[i];
            if (key === 'removeListener') continue;
            this.removeAllListeners(key);
          }
          this.removeAllListeners('removeListener');
          this._events = objectCreate(null);
          this._eventsCount = 0;
          return this;
        }
  
        listeners = events[type];
  
        if (typeof listeners === 'function') {
          this.removeListener(type, listeners);
        } else if (listeners) {
          // LIFO order
          for (i = listeners.length - 1; i >= 0; i--) {
            this.removeListener(type, listeners[i]);
          }
        }
  
        return this;
      };
  
  function _listeners(target, type, unwrap) {
    var events = target._events;
  
    if (!events)
      return [];
  
    var evlistener = events[type];
    if (!evlistener)
      return [];
  
    if (typeof evlistener === 'function')
      return unwrap ? [evlistener.listener || evlistener] : [evlistener];
  
    return unwrap ? unwrapListeners(evlistener) : arrayClone(evlistener, evlistener.length);
  }
  
  EventEmitter.prototype.listeners = function listeners(type) {
    return _listeners(this, type, true);
  };
  
  EventEmitter.prototype.rawListeners = function rawListeners(type) {
    return _listeners(this, type, false);
  };
  
  EventEmitter.listenerCount = function(emitter, type) {
    if (typeof emitter.listenerCount === 'function') {
      return emitter.listenerCount(type);
    } else {
      return listenerCount.call(emitter, type);
    }
  };
  
  EventEmitter.prototype.listenerCount = listenerCount;
  function listenerCount(type) {
    var events = this._events;
  
    if (events) {
      var evlistener = events[type];
  
      if (typeof evlistener === 'function') {
        return 1;
      } else if (evlistener) {
        return evlistener.length;
      }
    }
  
    return 0;
  }
  
  EventEmitter.prototype.eventNames = function eventNames() {
    return this._eventsCount > 0 ? Reflect.ownKeys(this._events) : [];
  };
  
  // About 1.5x faster than the two-arg version of Array#splice().
  function spliceOne(list, index) {
    for (var i = index, k = i + 1, n = list.length; k < n; i += 1, k += 1)
      list[i] = list[k];
    list.pop();
  }
  
  function arrayClone(arr, n) {
    var copy = new Array(n);
    for (var i = 0; i < n; ++i)
      copy[i] = arr[i];
    return copy;
  }
  
  function unwrapListeners(arr) {
    var ret = new Array(arr.length);
    for (var i = 0; i < ret.length; ++i) {
      ret[i] = arr[i].listener || arr[i];
    }
    return ret;
  }
  
  function objectCreatePolyfill(proto) {
    var F = function() {};
    F.prototype = proto;
    return new F;
  }
  function objectKeysPolyfill(obj) {
    var keys = [];
    for (var k in obj) if (Object.prototype.hasOwnProperty.call(obj, k)) {
      keys.push(k);
    }
    return k;
  }
  function functionBindPolyfill(context) {
    var fn = this;
    return function () {
      return fn.apply(context, arguments);
    };
  }
  
  },{}],5:[function(require,module,exports){
  exports.read = function (buffer, offset, isLE, mLen, nBytes) {
    var e, m
    var eLen = (nBytes * 8) - mLen - 1
    var eMax = (1 << eLen) - 1
    var eBias = eMax >> 1
    var nBits = -7
    var i = isLE ? (nBytes - 1) : 0
    var d = isLE ? -1 : 1
    var s = buffer[offset + i]
  
    i += d
  
    e = s & ((1 << (-nBits)) - 1)
    s >>= (-nBits)
    nBits += eLen
    for (; nBits > 0; e = (e * 256) + buffer[offset + i], i += d, nBits -= 8) {}
  
    m = e & ((1 << (-nBits)) - 1)
    e >>= (-nBits)
    nBits += mLen
    for (; nBits > 0; m = (m * 256) + buffer[offset + i], i += d, nBits -= 8) {}
  
    if (e === 0) {
      e = 1 - eBias
    } else if (e === eMax) {
      return m ? NaN : ((s ? -1 : 1) * Infinity)
    } else {
      m = m + Math.pow(2, mLen)
      e = e - eBias
    }
    return (s ? -1 : 1) * m * Math.pow(2, e - mLen)
  }
  
  exports.write = function (buffer, value, offset, isLE, mLen, nBytes) {
    var e, m, c
    var eLen = (nBytes * 8) - mLen - 1
    var eMax = (1 << eLen) - 1
    var eBias = eMax >> 1
    var rt = (mLen === 23 ? Math.pow(2, -24) - Math.pow(2, -77) : 0)
    var i = isLE ? 0 : (nBytes - 1)
    var d = isLE ? 1 : -1
    var s = value < 0 || (value === 0 && 1 / value < 0) ? 1 : 0
  
    value = Math.abs(value)
  
    if (isNaN(value) || value === Infinity) {
      m = isNaN(value) ? 1 : 0
      e = eMax
    } else {
      e = Math.floor(Math.log(value) / Math.LN2)
      if (value * (c = Math.pow(2, -e)) < 1) {
        e--
        c *= 2
      }
      if (e + eBias >= 1) {
        value += rt / c
      } else {
        value += rt * Math.pow(2, 1 - eBias)
      }
      if (value * c >= 2) {
        e++
        c /= 2
      }
  
      if (e + eBias >= eMax) {
        m = 0
        e = eMax
      } else if (e + eBias >= 1) {
        m = ((value * c) - 1) * Math.pow(2, mLen)
        e = e + eBias
      } else {
        m = value * Math.pow(2, eBias - 1) * Math.pow(2, mLen)
        e = 0
      }
    }
  
    for (; mLen >= 8; buffer[offset + i] = m & 0xff, i += d, m /= 256, mLen -= 8) {}
  
    e = (e << mLen) | m
    eLen += mLen
    for (; eLen > 0; buffer[offset + i] = e & 0xff, i += d, e /= 256, eLen -= 8) {}
  
    buffer[offset + i - d] |= s * 128
  }
  
  },{}],6:[function(require,module,exports){
  /*!
   * Determine if an object is a Buffer
   *
   * @author   Feross Aboukhadijeh <https://feross.org>
   * @license  MIT
   */
  
  // The _isBuffer check is for Safari 5-7 support, because it's missing
  // Object.prototype.constructor. Remove this eventually
  module.exports = function (obj) {
    return obj != null && (isBuffer(obj) || isSlowBuffer(obj) || !!obj._isBuffer)
  }
  
  function isBuffer (obj) {
    return !!obj.constructor && typeof obj.constructor.isBuffer === 'function' && obj.constructor.isBuffer(obj)
  }
  
  // For Node v0.10 support. Remove this eventually.
  function isSlowBuffer (obj) {
    return typeof obj.readFloatLE === 'function' && typeof obj.slice === 'function' && isBuffer(obj.slice(0, 0))
  }
  
  },{}],7:[function(require,module,exports){
  // shim for using process in browser
  var process = module.exports = {};
  
  // cached from whatever global is present so that test runners that stub it
  // don't break things.  But we need to wrap it in a try catch in case it is
  // wrapped in strict mode code which doesn't define any globals.  It's inside a
  // function because try/catches deoptimize in certain engines.
  
  var cachedSetTimeout;
  var cachedClearTimeout;
  
  function defaultSetTimout() {
      throw new Error('setTimeout has not been defined');
  }
  function defaultClearTimeout () {
      throw new Error('clearTimeout has not been defined');
  }
  (function () {
      try {
          if (typeof setTimeout === 'function') {
              cachedSetTimeout = setTimeout;
          } else {
              cachedSetTimeout = defaultSetTimout;
          }
      } catch (e) {
          cachedSetTimeout = defaultSetTimout;
      }
      try {
          if (typeof clearTimeout === 'function') {
              cachedClearTimeout = clearTimeout;
          } else {
              cachedClearTimeout = defaultClearTimeout;
          }
      } catch (e) {
          cachedClearTimeout = defaultClearTimeout;
      }
  } ())
  function runTimeout(fun) {
      if (cachedSetTimeout === setTimeout) {
          //normal enviroments in sane situations
          return setTimeout(fun, 0);
      }
      // if setTimeout wasn't available but was latter defined
      if ((cachedSetTimeout === defaultSetTimout || !cachedSetTimeout) && setTimeout) {
          cachedSetTimeout = setTimeout;
          return setTimeout(fun, 0);
      }
      try {
          // when when somebody has screwed with setTimeout but no I.E. maddness
          return cachedSetTimeout(fun, 0);
      } catch(e){
          try {
              // When we are in I.E. but the script has been evaled so I.E. doesn't trust the global object when called normally
              return cachedSetTimeout.call(null, fun, 0);
          } catch(e){
              // same as above but when it's a version of I.E. that must have the global object for 'this', hopfully our context correct otherwise it will throw a global error
              return cachedSetTimeout.call(this, fun, 0);
          }
      }
  
  
  }
  function runClearTimeout(marker) {
      if (cachedClearTimeout === clearTimeout) {
          //normal enviroments in sane situations
          return clearTimeout(marker);
      }
      // if clearTimeout wasn't available but was latter defined
      if ((cachedClearTimeout === defaultClearTimeout || !cachedClearTimeout) && clearTimeout) {
          cachedClearTimeout = clearTimeout;
          return clearTimeout(marker);
      }
      try {
          // when when somebody has screwed with setTimeout but no I.E. maddness
          return cachedClearTimeout(marker);
      } catch (e){
          try {
              // When we are in I.E. but the script has been evaled so I.E. doesn't  trust the global object when called normally
              return cachedClearTimeout.call(null, marker);
          } catch (e){
              // same as above but when it's a version of I.E. that must have the global object for 'this', hopfully our context correct otherwise it will throw a global error.
              // Some versions of I.E. have different rules for clearTimeout vs setTimeout
              return cachedClearTimeout.call(this, marker);
          }
      }
  
  
  
  }
  var queue = [];
  var draining = false;
  var currentQueue;
  var queueIndex = -1;
  
  function cleanUpNextTick() {
      if (!draining || !currentQueue) {
          return;
      }
      draining = false;
      if (currentQueue.length) {
          queue = currentQueue.concat(queue);
      } else {
          queueIndex = -1;
      }
      if (queue.length) {
          drainQueue();
      }
  }
  
  function drainQueue() {
      if (draining) {
          return;
      }
      var timeout = runTimeout(cleanUpNextTick);
      draining = true;
  
      var len = queue.length;
      while(len) {
          currentQueue = queue;
          queue = [];
          while (++queueIndex < len) {
              if (currentQueue) {
                  currentQueue[queueIndex].run();
              }
          }
          queueIndex = -1;
          len = queue.length;
      }
      currentQueue = null;
      draining = false;
      runClearTimeout(timeout);
  }
  
  process.nextTick = function (fun) {
      var args = new Array(arguments.length - 1);
      if (arguments.length > 1) {
          for (var i = 1; i < arguments.length; i++) {
              args[i - 1] = arguments[i];
          }
      }
      queue.push(new Item(fun, args));
      if (queue.length === 1 && !draining) {
          runTimeout(drainQueue);
      }
  };
  
  // v8 likes predictible objects
  function Item(fun, array) {
      this.fun = fun;
      this.array = array;
  }
  Item.prototype.run = function () {
      this.fun.apply(null, this.array);
  };
  process.title = 'browser';
  process.browser = true;
  process.env = {};
  process.argv = [];
  process.version = ''; // empty string to avoid regexp issues
  process.versions = {};
  
  function noop() {}
  
  process.on = noop;
  process.addListener = noop;
  process.once = noop;
  process.off = noop;
  process.removeListener = noop;
  process.removeAllListeners = noop;
  process.emit = noop;
  process.prependListener = noop;
  process.prependOnceListener = noop;
  
  process.listeners = function (name) { return [] }
  
  process.binding = function (name) {
      throw new Error('process.binding is not supported');
  };
  
  process.cwd = function () { return '/' };
  process.chdir = function (dir) {
      throw new Error('process.chdir is not supported');
  };
  process.umask = function() { return 0; };
  
  },{}],8:[function(require,module,exports){
  (function (setImmediate,clearImmediate){
  var nextTick = require('process/browser.js').nextTick;
  var apply = Function.prototype.apply;
  var slice = Array.prototype.slice;
  var immediateIds = {};
  var nextImmediateId = 0;
  
  // DOM APIs, for completeness
  
  exports.setTimeout = function() {
    return new Timeout(apply.call(setTimeout, window, arguments), clearTimeout);
  };
  exports.setInterval = function() {
    return new Timeout(apply.call(setInterval, window, arguments), clearInterval);
  };
  exports.clearTimeout =
  exports.clearInterval = function(timeout) { timeout.close(); };
  
  function Timeout(id, clearFn) {
    this._id = id;
    this._clearFn = clearFn;
  }
  Timeout.prototype.unref = Timeout.prototype.ref = function() {};
  Timeout.prototype.close = function() {
    this._clearFn.call(window, this._id);
  };
  
  // Does not start the time, just sets up the members needed.
  exports.enroll = function(item, msecs) {
    clearTimeout(item._idleTimeoutId);
    item._idleTimeout = msecs;
  };
  
  exports.unenroll = function(item) {
    clearTimeout(item._idleTimeoutId);
    item._idleTimeout = -1;
  };
  
  exports._unrefActive = exports.active = function(item) {
    clearTimeout(item._idleTimeoutId);
  
    var msecs = item._idleTimeout;
    if (msecs >= 0) {
      item._idleTimeoutId = setTimeout(function onTimeout() {
        if (item._onTimeout)
          item._onTimeout();
      }, msecs);
    }
  };
  
  // That's not how node.js implements it but the exposed api is the same.
  exports.setImmediate = typeof setImmediate === "function" ? setImmediate : function(fn) {
    var id = nextImmediateId++;
    var args = arguments.length < 2 ? false : slice.call(arguments, 1);
  
    immediateIds[id] = true;
  
    nextTick(function onNextTick() {
      if (immediateIds[id]) {
        // fn.call() is faster so we optimize for the common use-case
        // @see http://jsperf.com/call-apply-segu
        if (args) {
          fn.apply(null, args);
        } else {
          fn.call(null);
        }
        // Prevent ids from leaking
        exports.clearImmediate(id);
      }
    });
  
    return id;
  };
  
  exports.clearImmediate = typeof clearImmediate === "function" ? clearImmediate : function(id) {
    delete immediateIds[id];
  };
  }).call(this,require("timers").setImmediate,require("timers").clearImmediate)
  },{"process/browser.js":7,"timers":8}],9:[function(require,module,exports){
  
  var Peer = require('simple-peer');
  var peer;
  var localVideo;
  var localStream;
  var remoteVideo;
  var peerConnection;
  var uuid;
  var serverConnection;
  
  var peerConnectionConfig = {
    'iceServers': [
      {'urls': 'stun:stun.stunprotocol.org:3478'},
      {'urls': 'stun:stun.l.google.com:19302'},
    ]
  };
  
  function pageReady() {
    uuid = createUUID();
  
    localVideo = document.getElementById('localVideo');
    remoteVideo = document.getElementById('remoteVideo');
  
    serverConnection = new WebSocket('wss://' + window.location.hostname + ':8443');
    serverConnection.onmessage = gotMessageFromServer;
  
    var constraints = {
      video: true,
      audio: true,
    };
  
    if(navigator.mediaDevices.getUserMedia) {
      navigator.mediaDevices.getUserMedia(constraints).then(getUserMediaSuccess).catch(errorHandler);
    } else {
      alert('Your browser does not support getUserMedia API');
    }
  }
  
  window.PageReady=function(){pageReady()};
  window.Start=function(isCaller){start(isCaller)};
  
  function getUserMediaSuccess(stream) {
    localStream = stream;
    localVideo.srcObject = stream;
  }
  
  function start(isCaller) {
  
    peer = new Peer ({
      initiator: isCaller?true:false,
      channelConfig: {},
      channelName: '<random string>',
      config: { iceServers: [{ urls: 'stun:stun.l.google.com:19302' }, { urls: 'stun:global.stun.twilio.com:3478?transport=udp' }] },
      constraints: {},
      offerConstraints: {},
      answerConstraints: {},
      sdpTransform: function (sdp) { return sdp },
      stream: localStream,
      streams: [],
      trickle: true,
      allowHalfTrickle: false,
      wrtc: {}, // RTCPeerConnection/RTCSessionDescription/RTCIceCandidate
      objectMode: false
    });
    //peerConnection = new RTCPeerConnection(peerConnectionConfig);
    //peerConnection.onicecandidate = gotIceCandidate;
    peer.on('signal', function (data) {
        if(data!=null){
          serverConnection.send(JSON.stringify(data));
  
        }
    });
    peer.on('stream', function (stream) {
      remoteVideo.srcObject = stream;
    })
  
  
    //peerConnection.ontrack = gotRemoteStream;
    peerConnection.addStream(localStream);
  
    /* if(isCaller) {
      peerConnection.createOffer().then(createdDescription).catch(errorHandler);
    } */
  }
  
  function gotMessageFromServer(message) {
    if(!peer) start(false);
    peer.signal(message);
  
   /*  var signal = JSON.parse(message.data);
  
    // Ignore messages from ourself
    if(signal.uuid == uuid) return;
  
    if(signal.sdp) {
      peerConnection.setRemoteDescription(new RTCSessionDescription(signal.sdp)).then(function() {
        // Only create answers in response to offers
        if(signal.sdp.type == 'offer') {
          peerConnection.createAnswer().then(createdDescription).catch(errorHandler);
        }
      }).catch(errorHandler);
    } else if(signal.ice) {
      peerConnection.addIceCandidate(new RTCIceCandidate(signal.ice)).catch(errorHandler);
    } */
  }
  
  /* function gotIceCandidate(event) {
    if(event.candidate != null) {
      serverConnection.send(JSON.stringify({'ice': event.candidate, 'uuid': uuid}));
    }
  } */
  
  /* function createdDescription(description) {
    console.log('got description');
  
    peerConnection.setLocalDescription(description).then(function() {
      serverConnection.send(JSON.stringify({'sdp': peerConnection.localDescription, 'uuid': uuid}));
    }).catch(errorHandler);
  } */
  
  /* function gotRemoteStream(event) {
    console.log('got remote stream');
    remoteVideo.srcObject = event.streams[0];
  }
   */
  function errorHandler(error) {
    console.log(error);
  }
  
  // Taken from http://stackoverflow.com/a/105074/515584
  // Strictly speaking, it's not a real UUID, but it gets the job done here
  function createUUID() {
    function s4() {
      return Math.floor((1 + Math.random()) * 0x10000).toString(16).substring(1);
    }
  
    return s4() + s4() + '-' + s4() + '-' + s4() + '-' + s4() + '-' + s4() + s4() + s4();
  }
  
  },{"simple-peer":29}],10:[function(require,module,exports){
  (function (Buffer){
  // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  
  // NOTE: These type checking functions intentionally don't use `instanceof`
  // because it is fragile and can be easily faked with `Object.create()`.
  
  function isArray(arg) {
    if (Array.isArray) {
      return Array.isArray(arg);
    }
    return objectToString(arg) === '[object Array]';
  }
  exports.isArray = isArray;
  
  function isBoolean(arg) {
    return typeof arg === 'boolean';
  }
  exports.isBoolean = isBoolean;
  
  function isNull(arg) {
    return arg === null;
  }
  exports.isNull = isNull;
  
  function isNullOrUndefined(arg) {
    return arg == null;
  }
  exports.isNullOrUndefined = isNullOrUndefined;
  
  function isNumber(arg) {
    return typeof arg === 'number';
  }
  exports.isNumber = isNumber;
  
  function isString(arg) {
    return typeof arg === 'string';
  }
  exports.isString = isString;
  
  function isSymbol(arg) {
    return typeof arg === 'symbol';
  }
  exports.isSymbol = isSymbol;
  
  function isUndefined(arg) {
    return arg === void 0;
  }
  exports.isUndefined = isUndefined;
  
  function isRegExp(re) {
    return objectToString(re) === '[object RegExp]';
  }
  exports.isRegExp = isRegExp;
  
  function isObject(arg) {
    return typeof arg === 'object' && arg !== null;
  }
  exports.isObject = isObject;
  
  function isDate(d) {
    return objectToString(d) === '[object Date]';
  }
  exports.isDate = isDate;
  
  function isError(e) {
    return (objectToString(e) === '[object Error]' || e instanceof Error);
  }
  exports.isError = isError;
  
  function isFunction(arg) {
    return typeof arg === 'function';
  }
  exports.isFunction = isFunction;
  
  function isPrimitive(arg) {
    return arg === null ||
           typeof arg === 'boolean' ||
           typeof arg === 'number' ||
           typeof arg === 'string' ||
           typeof arg === 'symbol' ||  // ES6 symbol
           typeof arg === 'undefined';
  }
  exports.isPrimitive = isPrimitive;
  
  exports.isBuffer = Buffer.isBuffer;
  
  function objectToString(o) {
    return Object.prototype.toString.call(o);
  }
  
  }).call(this,{"isBuffer":require("../../../../AppData/Roaming/npm/node_modules/browserify/node_modules/is-buffer/index.js")})
  },{"../../../../AppData/Roaming/npm/node_modules/browserify/node_modules/is-buffer/index.js":6}],11:[function(require,module,exports){
  (function (process){
  /* eslint-env browser */
  
  /**
   * This is the web browser implementation of `debug()`.
   */
  
  exports.log = log;
  exports.formatArgs = formatArgs;
  exports.save = save;
  exports.load = load;
  exports.useColors = useColors;
  exports.storage = localstorage();
  
  /**
   * Colors.
   */
  
  exports.colors = [
  	'#0000CC',
  	'#0000FF',
  	'#0033CC',
  	'#0033FF',
  	'#0066CC',
  	'#0066FF',
  	'#0099CC',
  	'#0099FF',
  	'#00CC00',
  	'#00CC33',
  	'#00CC66',
  	'#00CC99',
  	'#00CCCC',
  	'#00CCFF',
  	'#3300CC',
  	'#3300FF',
  	'#3333CC',
  	'#3333FF',
  	'#3366CC',
  	'#3366FF',
  	'#3399CC',
  	'#3399FF',
  	'#33CC00',
  	'#33CC33',
  	'#33CC66',
  	'#33CC99',
  	'#33CCCC',
  	'#33CCFF',
  	'#6600CC',
  	'#6600FF',
  	'#6633CC',
  	'#6633FF',
  	'#66CC00',
  	'#66CC33',
  	'#9900CC',
  	'#9900FF',
  	'#9933CC',
  	'#9933FF',
  	'#99CC00',
  	'#99CC33',
  	'#CC0000',
  	'#CC0033',
  	'#CC0066',
  	'#CC0099',
  	'#CC00CC',
  	'#CC00FF',
  	'#CC3300',
  	'#CC3333',
  	'#CC3366',
  	'#CC3399',
  	'#CC33CC',
  	'#CC33FF',
  	'#CC6600',
  	'#CC6633',
  	'#CC9900',
  	'#CC9933',
  	'#CCCC00',
  	'#CCCC33',
  	'#FF0000',
  	'#FF0033',
  	'#FF0066',
  	'#FF0099',
  	'#FF00CC',
  	'#FF00FF',
  	'#FF3300',
  	'#FF3333',
  	'#FF3366',
  	'#FF3399',
  	'#FF33CC',
  	'#FF33FF',
  	'#FF6600',
  	'#FF6633',
  	'#FF9900',
  	'#FF9933',
  	'#FFCC00',
  	'#FFCC33'
  ];
  
  /**
   * Currently only WebKit-based Web Inspectors, Firefox >= v31,
   * and the Firebug extension (any Firefox version) are known
   * to support "%c" CSS customizations.
   *
   * TODO: add a `localStorage` variable to explicitly enable/disable colors
   */
  
  // eslint-disable-next-line complexity
  function useColors() {
  	// NB: In an Electron preload script, document will be defined but not fully
  	// initialized. Since we know we're in Chrome, we'll just detect this case
  	// explicitly
  	if (typeof window !== 'undefined' && window.process && (window.process.type === 'renderer' || window.process.__nwjs)) {
  		return true;
  	}
  
  	// Internet Explorer and Edge do not support colors.
  	if (typeof navigator !== 'undefined' && navigator.userAgent && navigator.userAgent.toLowerCase().match(/(edge|trident)\/(\d+)/)) {
  		return false;
  	}
  
  	// Is webkit? http://stackoverflow.com/a/16459606/376773
  	// document is undefined in react-native: https://github.com/facebook/react-native/pull/1632
  	return (typeof document !== 'undefined' && document.documentElement && document.documentElement.style && document.documentElement.style.WebkitAppearance) ||
  		// Is firebug? http://stackoverflow.com/a/398120/376773
  		(typeof window !== 'undefined' && window.console && (window.console.firebug || (window.console.exception && window.console.table))) ||
  		// Is firefox >= v31?
  		// https://developer.mozilla.org/en-US/docs/Tools/Web_Console#Styling_messages
  		(typeof navigator !== 'undefined' && navigator.userAgent && navigator.userAgent.toLowerCase().match(/firefox\/(\d+)/) && parseInt(RegExp.$1, 10) >= 31) ||
  		// Double check webkit in userAgent just in case we are in a worker
  		(typeof navigator !== 'undefined' && navigator.userAgent && navigator.userAgent.toLowerCase().match(/applewebkit\/(\d+)/));
  }
  
  /**
   * Colorize log arguments if enabled.
   *
   * @api public
   */
  
  function formatArgs(args) {
  	args[0] = (this.useColors ? '%c' : '') +
  		this.namespace +
  		(this.useColors ? ' %c' : ' ') +
  		args[0] +
  		(this.useColors ? '%c ' : ' ') +
  		'+' + module.exports.humanize(this.diff);
  
  	if (!this.useColors) {
  		return;
  	}
  
  	const c = 'color: ' + this.color;
  	args.splice(1, 0, c, 'color: inherit');
  
  	// The final "%c" is somewhat tricky, because there could be other
  	// arguments passed either before or after the %c, so we need to
  	// figure out the correct index to insert the CSS into
  	let index = 0;
  	let lastC = 0;
  	args[0].replace(/%[a-zA-Z%]/g, match => {
  		if (match === '%%') {
  			return;
  		}
  		index++;
  		if (match === '%c') {
  			// We only are interested in the *last* %c
  			// (the user may have provided their own)
  			lastC = index;
  		}
  	});
  
  	args.splice(lastC, 0, c);
  }
  
  /**
   * Invokes `console.log()` when available.
   * No-op when `console.log` is not a "function".
   *
   * @api public
   */
  function log(...args) {
  	// This hackery is required for IE8/9, where
  	// the `console.log` function doesn't have 'apply'
  	return typeof console === 'object' &&
  		console.log &&
  		console.log(...args);
  }
  
  /**
   * Save `namespaces`.
   *
   * @param {String} namespaces
   * @api private
   */
  function save(namespaces) {
  	try {
  		if (namespaces) {
  			exports.storage.setItem('debug', namespaces);
  		} else {
  			exports.storage.removeItem('debug');
  		}
  	} catch (error) {
  		// Swallow
  		// XXX (@Qix-) should we be logging these?
  	}
  }
  
  /**
   * Load `namespaces`.
   *
   * @return {String} returns the previously persisted debug modes
   * @api private
   */
  function load() {
  	let r;
  	try {
  		r = exports.storage.getItem('debug');
  	} catch (error) {
  		// Swallow
  		// XXX (@Qix-) should we be logging these?
  	}
  
  	// If debug isn't set in LS, and we're in Electron, try to load $DEBUG
  	if (!r && typeof process !== 'undefined' && 'env' in process) {
  		r = process.env.DEBUG;
  	}
  
  	return r;
  }
  
  /**
   * Localstorage attempts to return the localstorage.
   *
   * This is necessary because safari throws
   * when a user disables cookies/localstorage
   * and you attempt to access it.
   *
   * @return {LocalStorage}
   * @api private
   */
  
  function localstorage() {
  	try {
  		// TVMLKit (Apple TV JS Runtime) does not have a window object, just localStorage in the global context
  		// The Browser also has localStorage in the global context.
  		return localStorage;
  	} catch (error) {
  		// Swallow
  		// XXX (@Qix-) should we be logging these?
  	}
  }
  
  module.exports = require('./common')(exports);
  
  const {formatters} = module.exports;
  
  /**
   * Map %j to `JSON.stringify()`, since no Web Inspectors do that by default.
   */
  
  formatters.j = function (v) {
  	try {
  		return JSON.stringify(v);
  	} catch (error) {
  		return '[UnexpectedJSONParseError]: ' + error.message;
  	}
  };
  
  }).call(this,require('_process'))
  },{"./common":12,"_process":7}],12:[function(require,module,exports){
  
  /**
   * This is the common logic for both the Node.js and web browser
   * implementations of `debug()`.
   */
  
  function setup(env) {
  	createDebug.debug = createDebug;
  	createDebug.default = createDebug;
  	createDebug.coerce = coerce;
  	createDebug.disable = disable;
  	createDebug.enable = enable;
  	createDebug.enabled = enabled;
  	createDebug.humanize = require('ms');
  
  	Object.keys(env).forEach(key => {
  		createDebug[key] = env[key];
  	});
  
  	/**
  	* Active `debug` instances.
  	*/
  	createDebug.instances = [];
  
  	/**
  	* The currently active debug mode names, and names to skip.
  	*/
  
  	createDebug.names = [];
  	createDebug.skips = [];
  
  	/**
  	* Map of special "%n" handling functions, for the debug "format" argument.
  	*
  	* Valid key names are a single, lower or upper-case letter, i.e. "n" and "N".
  	*/
  	createDebug.formatters = {};
  
  	/**
  	* Selects a color for a debug namespace
  	* @param {String} namespace The namespace string for the for the debug instance to be colored
  	* @return {Number|String} An ANSI color code for the given namespace
  	* @api private
  	*/
  	function selectColor(namespace) {
  		let hash = 0;
  
  		for (let i = 0; i < namespace.length; i++) {
  			hash = ((hash << 5) - hash) + namespace.charCodeAt(i);
  			hash |= 0; // Convert to 32bit integer
  		}
  
  		return createDebug.colors[Math.abs(hash) % createDebug.colors.length];
  	}
  	createDebug.selectColor = selectColor;
  
  	/**
  	* Create a debugger with the given `namespace`.
  	*
  	* @param {String} namespace
  	* @return {Function}
  	* @api public
  	*/
  	function createDebug(namespace) {
  		let prevTime;
  
  		function debug(...args) {
  			// Disabled?
  			if (!debug.enabled) {
  				return;
  			}
  
  			const self = debug;
  
  			// Set `diff` timestamp
  			const curr = Number(new Date());
  			const ms = curr - (prevTime || curr);
  			self.diff = ms;
  			self.prev = prevTime;
  			self.curr = curr;
  			prevTime = curr;
  
  			args[0] = createDebug.coerce(args[0]);
  
  			if (typeof args[0] !== 'string') {
  				// Anything else let's inspect with %O
  				args.unshift('%O');
  			}
  
  			// Apply any `formatters` transformations
  			let index = 0;
  			args[0] = args[0].replace(/%([a-zA-Z%])/g, (match, format) => {
  				// If we encounter an escaped % then don't increase the array index
  				if (match === '%%') {
  					return match;
  				}
  				index++;
  				const formatter = createDebug.formatters[format];
  				if (typeof formatter === 'function') {
  					const val = args[index];
  					match = formatter.call(self, val);
  
  					// Now we need to remove `args[index]` since it's inlined in the `format`
  					args.splice(index, 1);
  					index--;
  				}
  				return match;
  			});
  
  			// Apply env-specific formatting (colors, etc.)
  			createDebug.formatArgs.call(self, args);
  
  			const logFn = self.log || createDebug.log;
  			logFn.apply(self, args);
  		}
  
  		debug.namespace = namespace;
  		debug.enabled = createDebug.enabled(namespace);
  		debug.useColors = createDebug.useColors();
  		debug.color = selectColor(namespace);
  		debug.destroy = destroy;
  		debug.extend = extend;
  		// Debug.formatArgs = formatArgs;
  		// debug.rawLog = rawLog;
  
  		// env-specific initialization logic for debug instances
  		if (typeof createDebug.init === 'function') {
  			createDebug.init(debug);
  		}
  
  		createDebug.instances.push(debug);
  
  		return debug;
  	}
  
  	function destroy() {
  		const index = createDebug.instances.indexOf(this);
  		if (index !== -1) {
  			createDebug.instances.splice(index, 1);
  			return true;
  		}
  		return false;
  	}
  
  	function extend(namespace, delimiter) {
  		const newDebug = createDebug(this.namespace + (typeof delimiter === 'undefined' ? ':' : delimiter) + namespace);
  		newDebug.log = this.log;
  		return newDebug;
  	}
  
  	/**
  	* Enables a debug mode by namespaces. This can include modes
  	* separated by a colon and wildcards.
  	*
  	* @param {String} namespaces
  	* @api public
  	*/
  	function enable(namespaces) {
  		createDebug.save(namespaces);
  
  		createDebug.names = [];
  		createDebug.skips = [];
  
  		let i;
  		const split = (typeof namespaces === 'string' ? namespaces : '').split(/[\s,]+/);
  		const len = split.length;
  
  		for (i = 0; i < len; i++) {
  			if (!split[i]) {
  				// ignore empty strings
  				continue;
  			}
  
  			namespaces = split[i].replace(/\*/g, '.*?');
  
  			if (namespaces[0] === '-') {
  				createDebug.skips.push(new RegExp('^' + namespaces.substr(1) + '$'));
  			} else {
  				createDebug.names.push(new RegExp('^' + namespaces + '$'));
  			}
  		}
  
  		for (i = 0; i < createDebug.instances.length; i++) {
  			const instance = createDebug.instances[i];
  			instance.enabled = createDebug.enabled(instance.namespace);
  		}
  	}
  
  	/**
  	* Disable debug output.
  	*
  	* @return {String} namespaces
  	* @api public
  	*/
  	function disable() {
  		const namespaces = [
  			...createDebug.names.map(toNamespace),
  			...createDebug.skips.map(toNamespace).map(namespace => '-' + namespace)
  		].join(',');
  		createDebug.enable('');
  		return namespaces;
  	}
  
  	/**
  	* Returns true if the given mode name is enabled, false otherwise.
  	*
  	* @param {String} name
  	* @return {Boolean}
  	* @api public
  	*/
  	function enabled(name) {
  		if (name[name.length - 1] === '*') {
  			return true;
  		}
  
  		let i;
  		let len;
  
  		for (i = 0, len = createDebug.skips.length; i < len; i++) {
  			if (createDebug.skips[i].test(name)) {
  				return false;
  			}
  		}
  
  		for (i = 0, len = createDebug.names.length; i < len; i++) {
  			if (createDebug.names[i].test(name)) {
  				return true;
  			}
  		}
  
  		return false;
  	}
  
  	/**
  	* Convert regexp to namespace
  	*
  	* @param {RegExp} regxep
  	* @return {String} namespace
  	* @api private
  	*/
  	function toNamespace(regexp) {
  		return regexp.toString()
  			.substring(2, regexp.toString().length - 2)
  			.replace(/\.\*\?$/, '*');
  	}
  
  	/**
  	* Coerce `val`.
  	*
  	* @param {Mixed} val
  	* @return {Mixed}
  	* @api private
  	*/
  	function coerce(val) {
  		if (val instanceof Error) {
  			return val.stack || val.message;
  		}
  		return val;
  	}
  
  	createDebug.enable(createDebug.load());
  
  	return createDebug;
  }
  
  module.exports = setup;
  
  },{"ms":16}],13:[function(require,module,exports){
  // originally pulled out of simple-peer
  
  module.exports = function getBrowserRTC () {
    if (typeof window === 'undefined') return null
    var wrtc = {
      RTCPeerConnection: window.RTCPeerConnection || window.mozRTCPeerConnection ||
        window.webkitRTCPeerConnection,
      RTCSessionDescription: window.RTCSessionDescription ||
        window.mozRTCSessionDescription || window.webkitRTCSessionDescription,
      RTCIceCandidate: window.RTCIceCandidate || window.mozRTCIceCandidate ||
        window.webkitRTCIceCandidate
    }
    if (!wrtc.RTCPeerConnection) return null
    return wrtc
  }
  
  },{}],14:[function(require,module,exports){
  if (typeof Object.create === 'function') {
    // implementation from standard node.js 'util' module
    module.exports = function inherits(ctor, superCtor) {
      ctor.super_ = superCtor
      ctor.prototype = Object.create(superCtor.prototype, {
        constructor: {
          value: ctor,
          enumerable: false,
          writable: true,
          configurable: true
        }
      });
    };
  } else {
    // old school shim for old browsers
    module.exports = function inherits(ctor, superCtor) {
      ctor.super_ = superCtor
      var TempCtor = function () {}
      TempCtor.prototype = superCtor.prototype
      ctor.prototype = new TempCtor()
      ctor.prototype.constructor = ctor
    }
  }
  
  },{}],15:[function(require,module,exports){
  var toString = {}.toString;
  
  module.exports = Array.isArray || function (arr) {
    return toString.call(arr) == '[object Array]';
  };
  
  },{}],16:[function(require,module,exports){
  /**
   * Helpers.
   */
  
  var s = 1000;
  var m = s * 60;
  var h = m * 60;
  var d = h * 24;
  var w = d * 7;
  var y = d * 365.25;
  
  /**
   * Parse or format the given `val`.
   *
   * Options:
   *
   *  - `long` verbose formatting [false]
   *
   * @param {String|Number} val
   * @param {Object} [options]
   * @throws {Error} throw an error if val is not a non-empty string or a number
   * @return {String|Number}
   * @api public
   */
  
  module.exports = function(val, options) {
    options = options || {};
    var type = typeof val;
    if (type === 'string' && val.length > 0) {
      return parse(val);
    } else if (type === 'number' && isNaN(val) === false) {
      return options.long ? fmtLong(val) : fmtShort(val);
    }
    throw new Error(
      'val is not a non-empty string or a valid number. val=' +
        JSON.stringify(val)
    );
  };
  
  /**
   * Parse the given `str` and return milliseconds.
   *
   * @param {String} str
   * @return {Number}
   * @api private
   */
  
  function parse(str) {
    str = String(str);
    if (str.length > 100) {
      return;
    }
    var match = /^((?:\d+)?\-?\d?\.?\d+) *(milliseconds?|msecs?|ms|seconds?|secs?|s|minutes?|mins?|m|hours?|hrs?|h|days?|d|weeks?|w|years?|yrs?|y)?$/i.exec(
      str
    );
    if (!match) {
      return;
    }
    var n = parseFloat(match[1]);
    var type = (match[2] || 'ms').toLowerCase();
    switch (type) {
      case 'years':
      case 'year':
      case 'yrs':
      case 'yr':
      case 'y':
        return n * y;
      case 'weeks':
      case 'week':
      case 'w':
        return n * w;
      case 'days':
      case 'day':
      case 'd':
        return n * d;
      case 'hours':
      case 'hour':
      case 'hrs':
      case 'hr':
      case 'h':
        return n * h;
      case 'minutes':
      case 'minute':
      case 'mins':
      case 'min':
      case 'm':
        return n * m;
      case 'seconds':
      case 'second':
      case 'secs':
      case 'sec':
      case 's':
        return n * s;
      case 'milliseconds':
      case 'millisecond':
      case 'msecs':
      case 'msec':
      case 'ms':
        return n;
      default:
        return undefined;
    }
  }
  
  /**
   * Short format for `ms`.
   *
   * @param {Number} ms
   * @return {String}
   * @api private
   */
  
  function fmtShort(ms) {
    var msAbs = Math.abs(ms);
    if (msAbs >= d) {
      return Math.round(ms / d) + 'd';
    }
    if (msAbs >= h) {
      return Math.round(ms / h) + 'h';
    }
    if (msAbs >= m) {
      return Math.round(ms / m) + 'm';
    }
    if (msAbs >= s) {
      return Math.round(ms / s) + 's';
    }
    return ms + 'ms';
  }
  
  /**
   * Long format for `ms`.
   *
   * @param {Number} ms
   * @return {String}
   * @api private
   */
  
  function fmtLong(ms) {
    var msAbs = Math.abs(ms);
    if (msAbs >= d) {
      return plural(ms, msAbs, d, 'day');
    }
    if (msAbs >= h) {
      return plural(ms, msAbs, h, 'hour');
    }
    if (msAbs >= m) {
      return plural(ms, msAbs, m, 'minute');
    }
    if (msAbs >= s) {
      return plural(ms, msAbs, s, 'second');
    }
    return ms + ' ms';
  }
  
  /**
   * Pluralization helper.
   */
  
  function plural(ms, msAbs, n, name) {
    var isPlural = msAbs >= n * 1.5;
    return Math.round(ms / n) + ' ' + name + (isPlural ? 's' : '');
  }
  
  },{}],17:[function(require,module,exports){
  (function (process){
  'use strict';
  
  if (!process.version ||
      process.version.indexOf('v0.') === 0 ||
      process.version.indexOf('v1.') === 0 && process.version.indexOf('v1.8.') !== 0) {
    module.exports = { nextTick: nextTick };
  } else {
    module.exports = process
  }
  
  function nextTick(fn, arg1, arg2, arg3) {
    if (typeof fn !== 'function') {
      throw new TypeError('"callback" argument must be a function');
    }
    var len = arguments.length;
    var args, i;
    switch (len) {
    case 0:
    case 1:
      return process.nextTick(fn);
    case 2:
      return process.nextTick(function afterTickOne() {
        fn.call(null, arg1);
      });
    case 3:
      return process.nextTick(function afterTickTwo() {
        fn.call(null, arg1, arg2);
      });
    case 4:
      return process.nextTick(function afterTickThree() {
        fn.call(null, arg1, arg2, arg3);
      });
    default:
      args = new Array(len - 1);
      i = 0;
      while (i < args.length) {
        args[i++] = arguments[i];
      }
      return process.nextTick(function afterTick() {
        fn.apply(null, args);
      });
    }
  }
  
  
  }).call(this,require('_process'))
  },{"_process":7}],18:[function(require,module,exports){
  (function (process,global){
  'use strict'
  
  // limit of Crypto.getRandomValues()
  // https://developer.mozilla.org/en-US/docs/Web/API/Crypto/getRandomValues
  var MAX_BYTES = 65536
  
  // Node supports requesting up to this number of bytes
  // https://github.com/nodejs/node/blob/master/lib/internal/crypto/random.js#L48
  var MAX_UINT32 = 4294967295
  
  function oldBrowser () {
    throw new Error('Secure random number generation is not supported by this browser.\nUse Chrome, Firefox or Internet Explorer 11')
  }
  
  var Buffer = require('safe-buffer').Buffer
  var crypto = global.crypto || global.msCrypto
  
  if (crypto && crypto.getRandomValues) {
    module.exports = randomBytes
  } else {
    module.exports = oldBrowser
  }
  
  function randomBytes (size, cb) {
    // phantomjs needs to throw
    if (size > MAX_UINT32) throw new RangeError('requested too many random bytes')
  
    var bytes = Buffer.allocUnsafe(size)
  
    if (size > 0) {  // getRandomValues fails on IE if size == 0
      if (size > MAX_BYTES) { // this is the max bytes crypto.getRandomValues
        // can do at once see https://developer.mozilla.org/en-US/docs/Web/API/window.crypto.getRandomValues
        for (var generated = 0; generated < size; generated += MAX_BYTES) {
          // buffer.slice automatically checks if the end is past the end of
          // the buffer so we don't have to here
          crypto.getRandomValues(bytes.slice(generated, generated + MAX_BYTES))
        }
      } else {
        crypto.getRandomValues(bytes)
      }
    }
  
    if (typeof cb === 'function') {
      return process.nextTick(function () {
        cb(null, bytes)
      })
    }
  
    return bytes
  }
  
  }).call(this,require('_process'),typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
  },{"_process":7,"safe-buffer":28}],19:[function(require,module,exports){
  // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  
  // a duplex stream is just a stream that is both readable and writable.
  // Since JS doesn't have multiple prototypal inheritance, this class
  // prototypally inherits from Readable, and then parasitically from
  // Writable.
  
  'use strict';
  
  /*<replacement>*/
  
  var pna = require('process-nextick-args');
  /*</replacement>*/
  
  /*<replacement>*/
  var objectKeys = Object.keys || function (obj) {
    var keys = [];
    for (var key in obj) {
      keys.push(key);
    }return keys;
  };
  /*</replacement>*/
  
  module.exports = Duplex;
  
  /*<replacement>*/
  var util = require('core-util-is');
  util.inherits = require('inherits');
  /*</replacement>*/
  
  var Readable = require('./_stream_readable');
  var Writable = require('./_stream_writable');
  
  util.inherits(Duplex, Readable);
  
  {
    // avoid scope creep, the keys array can then be collected
    var keys = objectKeys(Writable.prototype);
    for (var v = 0; v < keys.length; v++) {
      var method = keys[v];
      if (!Duplex.prototype[method]) Duplex.prototype[method] = Writable.prototype[method];
    }
  }
  
  function Duplex(options) {
    if (!(this instanceof Duplex)) return new Duplex(options);
  
    Readable.call(this, options);
    Writable.call(this, options);
  
    if (options && options.readable === false) this.readable = false;
  
    if (options && options.writable === false) this.writable = false;
  
    this.allowHalfOpen = true;
    if (options && options.allowHalfOpen === false) this.allowHalfOpen = false;
  
    this.once('end', onend);
  }
  
  Object.defineProperty(Duplex.prototype, 'writableHighWaterMark', {
    // making it explicit this property is not enumerable
    // because otherwise some prototype manipulation in
    // userland will fail
    enumerable: false,
    get: function () {
      return this._writableState.highWaterMark;
    }
  });
  
  // the no-half-open enforcer
  function onend() {
    // if we allow half-open state, or if the writable side ended,
    // then we're ok.
    if (this.allowHalfOpen || this._writableState.ended) return;
  
    // no more data can be written.
    // But allow more writes to happen in this tick.
    pna.nextTick(onEndNT, this);
  }
  
  function onEndNT(self) {
    self.end();
  }
  
  Object.defineProperty(Duplex.prototype, 'destroyed', {
    get: function () {
      if (this._readableState === undefined || this._writableState === undefined) {
        return false;
      }
      return this._readableState.destroyed && this._writableState.destroyed;
    },
    set: function (value) {
      // we ignore the value if the stream
      // has not been initialized yet
      if (this._readableState === undefined || this._writableState === undefined) {
        return;
      }
  
      // backward compatibility, the user is explicitly
      // managing destroyed
      this._readableState.destroyed = value;
      this._writableState.destroyed = value;
    }
  });
  
  Duplex.prototype._destroy = function (err, cb) {
    this.push(null);
    this.end();
  
    pna.nextTick(cb, err);
  };
  },{"./_stream_readable":21,"./_stream_writable":23,"core-util-is":10,"inherits":14,"process-nextick-args":17}],20:[function(require,module,exports){
  // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  
  // a passthrough stream.
  // basically just the most minimal sort of Transform stream.
  // Every written chunk gets output as-is.
  
  'use strict';
  
  module.exports = PassThrough;
  
  var Transform = require('./_stream_transform');
  
  /*<replacement>*/
  var util = require('core-util-is');
  util.inherits = require('inherits');
  /*</replacement>*/
  
  util.inherits(PassThrough, Transform);
  
  function PassThrough(options) {
    if (!(this instanceof PassThrough)) return new PassThrough(options);
  
    Transform.call(this, options);
  }
  
  PassThrough.prototype._transform = function (chunk, encoding, cb) {
    cb(null, chunk);
  };
  },{"./_stream_transform":22,"core-util-is":10,"inherits":14}],21:[function(require,module,exports){
  (function (process,global){
  // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  
  'use strict';
  
  /*<replacement>*/
  
  var pna = require('process-nextick-args');
  /*</replacement>*/
  
  module.exports = Readable;
  
  /*<replacement>*/
  var isArray = require('isarray');
  /*</replacement>*/
  
  /*<replacement>*/
  var Duplex;
  /*</replacement>*/
  
  Readable.ReadableState = ReadableState;
  
  /*<replacement>*/
  var EE = require('events').EventEmitter;
  
  var EElistenerCount = function (emitter, type) {
    return emitter.listeners(type).length;
  };
  /*</replacement>*/
  
  /*<replacement>*/
  var Stream = require('./internal/streams/stream');
  /*</replacement>*/
  
  /*<replacement>*/
  
  var Buffer = require('safe-buffer').Buffer;
  var OurUint8Array = global.Uint8Array || function () {};
  function _uint8ArrayToBuffer(chunk) {
    return Buffer.from(chunk);
  }
  function _isUint8Array(obj) {
    return Buffer.isBuffer(obj) || obj instanceof OurUint8Array;
  }
  
  /*</replacement>*/
  
  /*<replacement>*/
  var util = require('core-util-is');
  util.inherits = require('inherits');
  /*</replacement>*/
  
  /*<replacement>*/
  var debugUtil = require('util');
  var debug = void 0;
  if (debugUtil && debugUtil.debuglog) {
    debug = debugUtil.debuglog('stream');
  } else {
    debug = function () {};
  }
  /*</replacement>*/
  
  var BufferList = require('./internal/streams/BufferList');
  var destroyImpl = require('./internal/streams/destroy');
  var StringDecoder;
  
  util.inherits(Readable, Stream);
  
  var kProxyEvents = ['error', 'close', 'destroy', 'pause', 'resume'];
  
  function prependListener(emitter, event, fn) {
    // Sadly this is not cacheable as some libraries bundle their own
    // event emitter implementation with them.
    if (typeof emitter.prependListener === 'function') return emitter.prependListener(event, fn);
  
    // This is a hack to make sure that our error handler is attached before any
    // userland ones.  NEVER DO THIS. This is here only because this code needs
    // to continue to work with older versions of Node.js that do not include
    // the prependListener() method. The goal is to eventually remove this hack.
    if (!emitter._events || !emitter._events[event]) emitter.on(event, fn);else if (isArray(emitter._events[event])) emitter._events[event].unshift(fn);else emitter._events[event] = [fn, emitter._events[event]];
  }
  
  function ReadableState(options, stream) {
    Duplex = Duplex || require('./_stream_duplex');
  
    options = options || {};
  
    // Duplex streams are both readable and writable, but share
    // the same options object.
    // However, some cases require setting options to different
    // values for the readable and the writable sides of the duplex stream.
    // These options can be provided separately as readableXXX and writableXXX.
    var isDuplex = stream instanceof Duplex;
  
    // object stream flag. Used to make read(n) ignore n and to
    // make all the buffer merging and length checks go away
    this.objectMode = !!options.objectMode;
  
    if (isDuplex) this.objectMode = this.objectMode || !!options.readableObjectMode;
  
    // the point at which it stops calling _read() to fill the buffer
    // Note: 0 is a valid value, means "don't call _read preemptively ever"
    var hwm = options.highWaterMark;
    var readableHwm = options.readableHighWaterMark;
    var defaultHwm = this.objectMode ? 16 : 16 * 1024;
  
    if (hwm || hwm === 0) this.highWaterMark = hwm;else if (isDuplex && (readableHwm || readableHwm === 0)) this.highWaterMark = readableHwm;else this.highWaterMark = defaultHwm;
  
    // cast to ints.
    this.highWaterMark = Math.floor(this.highWaterMark);
  
    // A linked list is used to store data chunks instead of an array because the
    // linked list can remove elements from the beginning faster than
    // array.shift()
    this.buffer = new BufferList();
    this.length = 0;
    this.pipes = null;
    this.pipesCount = 0;
    this.flowing = null;
    this.ended = false;
    this.endEmitted = false;
    this.reading = false;
  
    // a flag to be able to tell if the event 'readable'/'data' is emitted
    // immediately, or on a later tick.  We set this to true at first, because
    // any actions that shouldn't happen until "later" should generally also
    // not happen before the first read call.
    this.sync = true;
  
    // whenever we return null, then we set a flag to say
    // that we're awaiting a 'readable' event emission.
    this.needReadable = false;
    this.emittedReadable = false;
    this.readableListening = false;
    this.resumeScheduled = false;
  
    // has it been destroyed
    this.destroyed = false;
  
    // Crypto is kind of old and crusty.  Historically, its default string
    // encoding is 'binary' so we have to make this configurable.
    // Everything else in the universe uses 'utf8', though.
    this.defaultEncoding = options.defaultEncoding || 'utf8';
  
    // the number of writers that are awaiting a drain event in .pipe()s
    this.awaitDrain = 0;
  
    // if true, a maybeReadMore has been scheduled
    this.readingMore = false;
  
    this.decoder = null;
    this.encoding = null;
    if (options.encoding) {
      if (!StringDecoder) StringDecoder = require('string_decoder/').StringDecoder;
      this.decoder = new StringDecoder(options.encoding);
      this.encoding = options.encoding;
    }
  }
  
  function Readable(options) {
    Duplex = Duplex || require('./_stream_duplex');
  
    if (!(this instanceof Readable)) return new Readable(options);
  
    this._readableState = new ReadableState(options, this);
  
    // legacy
    this.readable = true;
  
    if (options) {
      if (typeof options.read === 'function') this._read = options.read;
  
      if (typeof options.destroy === 'function') this._destroy = options.destroy;
    }
  
    Stream.call(this);
  }
  
  Object.defineProperty(Readable.prototype, 'destroyed', {
    get: function () {
      if (this._readableState === undefined) {
        return false;
      }
      return this._readableState.destroyed;
    },
    set: function (value) {
      // we ignore the value if the stream
      // has not been initialized yet
      if (!this._readableState) {
        return;
      }
  
      // backward compatibility, the user is explicitly
      // managing destroyed
      this._readableState.destroyed = value;
    }
  });
  
  Readable.prototype.destroy = destroyImpl.destroy;
  Readable.prototype._undestroy = destroyImpl.undestroy;
  Readable.prototype._destroy = function (err, cb) {
    this.push(null);
    cb(err);
  };
  
  // Manually shove something into the read() buffer.
  // This returns true if the highWaterMark has not been hit yet,
  // similar to how Writable.write() returns true if you should
  // write() some more.
  Readable.prototype.push = function (chunk, encoding) {
    var state = this._readableState;
    var skipChunkCheck;
  
    if (!state.objectMode) {
      if (typeof chunk === 'string') {
        encoding = encoding || state.defaultEncoding;
        if (encoding !== state.encoding) {
          chunk = Buffer.from(chunk, encoding);
          encoding = '';
        }
        skipChunkCheck = true;
      }
    } else {
      skipChunkCheck = true;
    }
  
    return readableAddChunk(this, chunk, encoding, false, skipChunkCheck);
  };
  
  // Unshift should *always* be something directly out of read()
  Readable.prototype.unshift = function (chunk) {
    return readableAddChunk(this, chunk, null, true, false);
  };
  
  function readableAddChunk(stream, chunk, encoding, addToFront, skipChunkCheck) {
    var state = stream._readableState;
    if (chunk === null) {
      state.reading = false;
      onEofChunk(stream, state);
    } else {
      var er;
      if (!skipChunkCheck) er = chunkInvalid(state, chunk);
      if (er) {
        stream.emit('error', er);
      } else if (state.objectMode || chunk && chunk.length > 0) {
        if (typeof chunk !== 'string' && !state.objectMode && Object.getPrototypeOf(chunk) !== Buffer.prototype) {
          chunk = _uint8ArrayToBuffer(chunk);
        }
  
        if (addToFront) {
          if (state.endEmitted) stream.emit('error', new Error('stream.unshift() after end event'));else addChunk(stream, state, chunk, true);
        } else if (state.ended) {
          stream.emit('error', new Error('stream.push() after EOF'));
        } else {
          state.reading = false;
          if (state.decoder && !encoding) {
            chunk = state.decoder.write(chunk);
            if (state.objectMode || chunk.length !== 0) addChunk(stream, state, chunk, false);else maybeReadMore(stream, state);
          } else {
            addChunk(stream, state, chunk, false);
          }
        }
      } else if (!addToFront) {
        state.reading = false;
      }
    }
  
    return needMoreData(state);
  }
  
  function addChunk(stream, state, chunk, addToFront) {
    if (state.flowing && state.length === 0 && !state.sync) {
      stream.emit('data', chunk);
      stream.read(0);
    } else {
      // update the buffer info.
      state.length += state.objectMode ? 1 : chunk.length;
      if (addToFront) state.buffer.unshift(chunk);else state.buffer.push(chunk);
  
      if (state.needReadable) emitReadable(stream);
    }
    maybeReadMore(stream, state);
  }
  
  function chunkInvalid(state, chunk) {
    var er;
    if (!_isUint8Array(chunk) && typeof chunk !== 'string' && chunk !== undefined && !state.objectMode) {
      er = new TypeError('Invalid non-string/buffer chunk');
    }
    return er;
  }
  
  // if it's past the high water mark, we can push in some more.
  // Also, if we have no data yet, we can stand some
  // more bytes.  This is to work around cases where hwm=0,
  // such as the repl.  Also, if the push() triggered a
  // readable event, and the user called read(largeNumber) such that
  // needReadable was set, then we ought to push more, so that another
  // 'readable' event will be triggered.
  function needMoreData(state) {
    return !state.ended && (state.needReadable || state.length < state.highWaterMark || state.length === 0);
  }
  
  Readable.prototype.isPaused = function () {
    return this._readableState.flowing === false;
  };
  
  // backwards compatibility.
  Readable.prototype.setEncoding = function (enc) {
    if (!StringDecoder) StringDecoder = require('string_decoder/').StringDecoder;
    this._readableState.decoder = new StringDecoder(enc);
    this._readableState.encoding = enc;
    return this;
  };
  
  // Don't raise the hwm > 8MB
  var MAX_HWM = 0x800000;
  function computeNewHighWaterMark(n) {
    if (n >= MAX_HWM) {
      n = MAX_HWM;
    } else {
      // Get the next highest power of 2 to prevent increasing hwm excessively in
      // tiny amounts
      n--;
      n |= n >>> 1;
      n |= n >>> 2;
      n |= n >>> 4;
      n |= n >>> 8;
      n |= n >>> 16;
      n++;
    }
    return n;
  }
  
  // This function is designed to be inlinable, so please take care when making
  // changes to the function body.
  function howMuchToRead(n, state) {
    if (n <= 0 || state.length === 0 && state.ended) return 0;
    if (state.objectMode) return 1;
    if (n !== n) {
      // Only flow one buffer at a time
      if (state.flowing && state.length) return state.buffer.head.data.length;else return state.length;
    }
    // If we're asking for more than the current hwm, then raise the hwm.
    if (n > state.highWaterMark) state.highWaterMark = computeNewHighWaterMark(n);
    if (n <= state.length) return n;
    // Don't have enough
    if (!state.ended) {
      state.needReadable = true;
      return 0;
    }
    return state.length;
  }
  
  // you can override either this method, or the async _read(n) below.
  Readable.prototype.read = function (n) {
    debug('read', n);
    n = parseInt(n, 10);
    var state = this._readableState;
    var nOrig = n;
  
    if (n !== 0) state.emittedReadable = false;
  
    // if we're doing read(0) to trigger a readable event, but we
    // already have a bunch of data in the buffer, then just trigger
    // the 'readable' event and move on.
    if (n === 0 && state.needReadable && (state.length >= state.highWaterMark || state.ended)) {
      debug('read: emitReadable', state.length, state.ended);
      if (state.length === 0 && state.ended) endReadable(this);else emitReadable(this);
      return null;
    }
  
    n = howMuchToRead(n, state);
  
    // if we've ended, and we're now clear, then finish it up.
    if (n === 0 && state.ended) {
      if (state.length === 0) endReadable(this);
      return null;
    }
  
    // All the actual chunk generation logic needs to be
    // *below* the call to _read.  The reason is that in certain
    // synthetic stream cases, such as passthrough streams, _read
    // may be a completely synchronous operation which may change
    // the state of the read buffer, providing enough data when
    // before there was *not* enough.
    //
    // So, the steps are:
    // 1. Figure out what the state of things will be after we do
    // a read from the buffer.
    //
    // 2. If that resulting state will trigger a _read, then call _read.
    // Note that this may be asynchronous, or synchronous.  Yes, it is
    // deeply ugly to write APIs this way, but that still doesn't mean
    // that the Readable class should behave improperly, as streams are
    // designed to be sync/async agnostic.
    // Take note if the _read call is sync or async (ie, if the read call
    // has returned yet), so that we know whether or not it's safe to emit
    // 'readable' etc.
    //
    // 3. Actually pull the requested chunks out of the buffer and return.
  
    // if we need a readable event, then we need to do some reading.
    var doRead = state.needReadable;
    debug('need readable', doRead);
  
    // if we currently have less than the highWaterMark, then also read some
    if (state.length === 0 || state.length - n < state.highWaterMark) {
      doRead = true;
      debug('length less than watermark', doRead);
    }
  
    // however, if we've ended, then there's no point, and if we're already
    // reading, then it's unnecessary.
    if (state.ended || state.reading) {
      doRead = false;
      debug('reading or ended', doRead);
    } else if (doRead) {
      debug('do read');
      state.reading = true;
      state.sync = true;
      // if the length is currently zero, then we *need* a readable event.
      if (state.length === 0) state.needReadable = true;
      // call internal read method
      this._read(state.highWaterMark);
      state.sync = false;
      // If _read pushed data synchronously, then `reading` will be false,
      // and we need to re-evaluate how much data we can return to the user.
      if (!state.reading) n = howMuchToRead(nOrig, state);
    }
  
    var ret;
    if (n > 0) ret = fromList(n, state);else ret = null;
  
    if (ret === null) {
      state.needReadable = true;
      n = 0;
    } else {
      state.length -= n;
    }
  
    if (state.length === 0) {
      // If we have nothing in the buffer, then we want to know
      // as soon as we *do* get something into the buffer.
      if (!state.ended) state.needReadable = true;
  
      // If we tried to read() past the EOF, then emit end on the next tick.
      if (nOrig !== n && state.ended) endReadable(this);
    }
  
    if (ret !== null) this.emit('data', ret);
  
    return ret;
  };
  
  function onEofChunk(stream, state) {
    if (state.ended) return;
    if (state.decoder) {
      var chunk = state.decoder.end();
      if (chunk && chunk.length) {
        state.buffer.push(chunk);
        state.length += state.objectMode ? 1 : chunk.length;
      }
    }
    state.ended = true;
  
    // emit 'readable' now to make sure it gets picked up.
    emitReadable(stream);
  }
  
  // Don't emit readable right away in sync mode, because this can trigger
  // another read() call => stack overflow.  This way, it might trigger
  // a nextTick recursion warning, but that's not so bad.
  function emitReadable(stream) {
    var state = stream._readableState;
    state.needReadable = false;
    if (!state.emittedReadable) {
      debug('emitReadable', state.flowing);
      state.emittedReadable = true;
      if (state.sync) pna.nextTick(emitReadable_, stream);else emitReadable_(stream);
    }
  }
  
  function emitReadable_(stream) {
    debug('emit readable');
    stream.emit('readable');
    flow(stream);
  }
  
  // at this point, the user has presumably seen the 'readable' event,
  // and called read() to consume some data.  that may have triggered
  // in turn another _read(n) call, in which case reading = true if
  // it's in progress.
  // However, if we're not ended, or reading, and the length < hwm,
  // then go ahead and try to read some more preemptively.
  function maybeReadMore(stream, state) {
    if (!state.readingMore) {
      state.readingMore = true;
      pna.nextTick(maybeReadMore_, stream, state);
    }
  }
  
  function maybeReadMore_(stream, state) {
    var len = state.length;
    while (!state.reading && !state.flowing && !state.ended && state.length < state.highWaterMark) {
      debug('maybeReadMore read 0');
      stream.read(0);
      if (len === state.length)
        // didn't get any data, stop spinning.
        break;else len = state.length;
    }
    state.readingMore = false;
  }
  
  // abstract method.  to be overridden in specific implementation classes.
  // call cb(er, data) where data is <= n in length.
  // for virtual (non-string, non-buffer) streams, "length" is somewhat
  // arbitrary, and perhaps not very meaningful.
  Readable.prototype._read = function (n) {
    this.emit('error', new Error('_read() is not implemented'));
  };
  
  Readable.prototype.pipe = function (dest, pipeOpts) {
    var src = this;
    var state = this._readableState;
  
    switch (state.pipesCount) {
      case 0:
        state.pipes = dest;
        break;
      case 1:
        state.pipes = [state.pipes, dest];
        break;
      default:
        state.pipes.push(dest);
        break;
    }
    state.pipesCount += 1;
    debug('pipe count=%d opts=%j', state.pipesCount, pipeOpts);
  
    var doEnd = (!pipeOpts || pipeOpts.end !== false) && dest !== process.stdout && dest !== process.stderr;
  
    var endFn = doEnd ? onend : unpipe;
    if (state.endEmitted) pna.nextTick(endFn);else src.once('end', endFn);
  
    dest.on('unpipe', onunpipe);
    function onunpipe(readable, unpipeInfo) {
      debug('onunpipe');
      if (readable === src) {
        if (unpipeInfo && unpipeInfo.hasUnpiped === false) {
          unpipeInfo.hasUnpiped = true;
          cleanup();
        }
      }
    }
  
    function onend() {
      debug('onend');
      dest.end();
    }
  
    // when the dest drains, it reduces the awaitDrain counter
    // on the source.  This would be more elegant with a .once()
    // handler in flow(), but adding and removing repeatedly is
    // too slow.
    var ondrain = pipeOnDrain(src);
    dest.on('drain', ondrain);
  
    var cleanedUp = false;
    function cleanup() {
      debug('cleanup');
      // cleanup event handlers once the pipe is broken
      dest.removeListener('close', onclose);
      dest.removeListener('finish', onfinish);
      dest.removeListener('drain', ondrain);
      dest.removeListener('error', onerror);
      dest.removeListener('unpipe', onunpipe);
      src.removeListener('end', onend);
      src.removeListener('end', unpipe);
      src.removeListener('data', ondata);
  
      cleanedUp = true;
  
      // if the reader is waiting for a drain event from this
      // specific writer, then it would cause it to never start
      // flowing again.
      // So, if this is awaiting a drain, then we just call it now.
      // If we don't know, then assume that we are waiting for one.
      if (state.awaitDrain && (!dest._writableState || dest._writableState.needDrain)) ondrain();
    }
  
    // If the user pushes more data while we're writing to dest then we'll end up
    // in ondata again. However, we only want to increase awaitDrain once because
    // dest will only emit one 'drain' event for the multiple writes.
    // => Introduce a guard on increasing awaitDrain.
    var increasedAwaitDrain = false;
    src.on('data', ondata);
    function ondata(chunk) {
      debug('ondata');
      increasedAwaitDrain = false;
      var ret = dest.write(chunk);
      if (false === ret && !increasedAwaitDrain) {
        // If the user unpiped during `dest.write()`, it is possible
        // to get stuck in a permanently paused state if that write
        // also returned false.
        // => Check whether `dest` is still a piping destination.
        if ((state.pipesCount === 1 && state.pipes === dest || state.pipesCount > 1 && indexOf(state.pipes, dest) !== -1) && !cleanedUp) {
          debug('false write response, pause', src._readableState.awaitDrain);
          src._readableState.awaitDrain++;
          increasedAwaitDrain = true;
        }
        src.pause();
      }
    }
  
    // if the dest has an error, then stop piping into it.
    // however, don't suppress the throwing behavior for this.
    function onerror(er) {
      debug('onerror', er);
      unpipe();
      dest.removeListener('error', onerror);
      if (EElistenerCount(dest, 'error') === 0) dest.emit('error', er);
    }
  
    // Make sure our error handler is attached before userland ones.
    prependListener(dest, 'error', onerror);
  
    // Both close and finish should trigger unpipe, but only once.
    function onclose() {
      dest.removeListener('finish', onfinish);
      unpipe();
    }
    dest.once('close', onclose);
    function onfinish() {
      debug('onfinish');
      dest.removeListener('close', onclose);
      unpipe();
    }
    dest.once('finish', onfinish);
  
    function unpipe() {
      debug('unpipe');
      src.unpipe(dest);
    }
  
    // tell the dest that it's being piped to
    dest.emit('pipe', src);
  
    // start the flow if it hasn't been started already.
    if (!state.flowing) {
      debug('pipe resume');
      src.resume();
    }
  
    return dest;
  };
  
  function pipeOnDrain(src) {
    return function () {
      var state = src._readableState;
      debug('pipeOnDrain', state.awaitDrain);
      if (state.awaitDrain) state.awaitDrain--;
      if (state.awaitDrain === 0 && EElistenerCount(src, 'data')) {
        state.flowing = true;
        flow(src);
      }
    };
  }
  
  Readable.prototype.unpipe = function (dest) {
    var state = this._readableState;
    var unpipeInfo = { hasUnpiped: false };
  
    // if we're not piping anywhere, then do nothing.
    if (state.pipesCount === 0) return this;
  
    // just one destination.  most common case.
    if (state.pipesCount === 1) {
      // passed in one, but it's not the right one.
      if (dest && dest !== state.pipes) return this;
  
      if (!dest) dest = state.pipes;
  
      // got a match.
      state.pipes = null;
      state.pipesCount = 0;
      state.flowing = false;
      if (dest) dest.emit('unpipe', this, unpipeInfo);
      return this;
    }
  
    // slow case. multiple pipe destinations.
  
    if (!dest) {
      // remove all.
      var dests = state.pipes;
      var len = state.pipesCount;
      state.pipes = null;
      state.pipesCount = 0;
      state.flowing = false;
  
      for (var i = 0; i < len; i++) {
        dests[i].emit('unpipe', this, unpipeInfo);
      }return this;
    }
  
    // try to find the right one.
    var index = indexOf(state.pipes, dest);
    if (index === -1) return this;
  
    state.pipes.splice(index, 1);
    state.pipesCount -= 1;
    if (state.pipesCount === 1) state.pipes = state.pipes[0];
  
    dest.emit('unpipe', this, unpipeInfo);
  
    return this;
  };
  
  // set up data events if they are asked for
  // Ensure readable listeners eventually get something
  Readable.prototype.on = function (ev, fn) {
    var res = Stream.prototype.on.call(this, ev, fn);
  
    if (ev === 'data') {
      // Start flowing on next tick if stream isn't explicitly paused
      if (this._readableState.flowing !== false) this.resume();
    } else if (ev === 'readable') {
      var state = this._readableState;
      if (!state.endEmitted && !state.readableListening) {
        state.readableListening = state.needReadable = true;
        state.emittedReadable = false;
        if (!state.reading) {
          pna.nextTick(nReadingNextTick, this);
        } else if (state.length) {
          emitReadable(this);
        }
      }
    }
  
    return res;
  };
  Readable.prototype.addListener = Readable.prototype.on;
  
  function nReadingNextTick(self) {
    debug('readable nexttick read 0');
    self.read(0);
  }
  
  // pause() and resume() are remnants of the legacy readable stream API
  // If the user uses them, then switch into old mode.
  Readable.prototype.resume = function () {
    var state = this._readableState;
    if (!state.flowing) {
      debug('resume');
      state.flowing = true;
      resume(this, state);
    }
    return this;
  };
  
  function resume(stream, state) {
    if (!state.resumeScheduled) {
      state.resumeScheduled = true;
      pna.nextTick(resume_, stream, state);
    }
  }
  
  function resume_(stream, state) {
    if (!state.reading) {
      debug('resume read 0');
      stream.read(0);
    }
  
    state.resumeScheduled = false;
    state.awaitDrain = 0;
    stream.emit('resume');
    flow(stream);
    if (state.flowing && !state.reading) stream.read(0);
  }
  
  Readable.prototype.pause = function () {
    debug('call pause flowing=%j', this._readableState.flowing);
    if (false !== this._readableState.flowing) {
      debug('pause');
      this._readableState.flowing = false;
      this.emit('pause');
    }
    return this;
  };
  
  function flow(stream) {
    var state = stream._readableState;
    debug('flow', state.flowing);
    while (state.flowing && stream.read() !== null) {}
  }
  
  // wrap an old-style stream as the async data source.
  // This is *not* part of the readable stream interface.
  // It is an ugly unfortunate mess of history.
  Readable.prototype.wrap = function (stream) {
    var _this = this;
  
    var state = this._readableState;
    var paused = false;
  
    stream.on('end', function () {
      debug('wrapped end');
      if (state.decoder && !state.ended) {
        var chunk = state.decoder.end();
        if (chunk && chunk.length) _this.push(chunk);
      }
  
      _this.push(null);
    });
  
    stream.on('data', function (chunk) {
      debug('wrapped data');
      if (state.decoder) chunk = state.decoder.write(chunk);
  
      // don't skip over falsy values in objectMode
      if (state.objectMode && (chunk === null || chunk === undefined)) return;else if (!state.objectMode && (!chunk || !chunk.length)) return;
  
      var ret = _this.push(chunk);
      if (!ret) {
        paused = true;
        stream.pause();
      }
    });
  
    // proxy all the other methods.
    // important when wrapping filters and duplexes.
    for (var i in stream) {
      if (this[i] === undefined && typeof stream[i] === 'function') {
        this[i] = function (method) {
          return function () {
            return stream[method].apply(stream, arguments);
          };
        }(i);
      }
    }
  
    // proxy certain important events.
    for (var n = 0; n < kProxyEvents.length; n++) {
      stream.on(kProxyEvents[n], this.emit.bind(this, kProxyEvents[n]));
    }
  
    // when we try to consume some more bytes, simply unpause the
    // underlying stream.
    this._read = function (n) {
      debug('wrapped _read', n);
      if (paused) {
        paused = false;
        stream.resume();
      }
    };
  
    return this;
  };
  
  Object.defineProperty(Readable.prototype, 'readableHighWaterMark', {
    // making it explicit this property is not enumerable
    // because otherwise some prototype manipulation in
    // userland will fail
    enumerable: false,
    get: function () {
      return this._readableState.highWaterMark;
    }
  });
  
  // exposed for testing purposes only.
  Readable._fromList = fromList;
  
  // Pluck off n bytes from an array of buffers.
  // Length is the combined lengths of all the buffers in the list.
  // This function is designed to be inlinable, so please take care when making
  // changes to the function body.
  function fromList(n, state) {
    // nothing buffered
    if (state.length === 0) return null;
  
    var ret;
    if (state.objectMode) ret = state.buffer.shift();else if (!n || n >= state.length) {
      // read it all, truncate the list
      if (state.decoder) ret = state.buffer.join('');else if (state.buffer.length === 1) ret = state.buffer.head.data;else ret = state.buffer.concat(state.length);
      state.buffer.clear();
    } else {
      // read part of list
      ret = fromListPartial(n, state.buffer, state.decoder);
    }
  
    return ret;
  }
  
  // Extracts only enough buffered data to satisfy the amount requested.
  // This function is designed to be inlinable, so please take care when making
  // changes to the function body.
  function fromListPartial(n, list, hasStrings) {
    var ret;
    if (n < list.head.data.length) {
      // slice is the same for buffers and strings
      ret = list.head.data.slice(0, n);
      list.head.data = list.head.data.slice(n);
    } else if (n === list.head.data.length) {
      // first chunk is a perfect match
      ret = list.shift();
    } else {
      // result spans more than one buffer
      ret = hasStrings ? copyFromBufferString(n, list) : copyFromBuffer(n, list);
    }
    return ret;
  }
  
  // Copies a specified amount of characters from the list of buffered data
  // chunks.
  // This function is designed to be inlinable, so please take care when making
  // changes to the function body.
  function copyFromBufferString(n, list) {
    var p = list.head;
    var c = 1;
    var ret = p.data;
    n -= ret.length;
    while (p = p.next) {
      var str = p.data;
      var nb = n > str.length ? str.length : n;
      if (nb === str.length) ret += str;else ret += str.slice(0, n);
      n -= nb;
      if (n === 0) {
        if (nb === str.length) {
          ++c;
          if (p.next) list.head = p.next;else list.head = list.tail = null;
        } else {
          list.head = p;
          p.data = str.slice(nb);
        }
        break;
      }
      ++c;
    }
    list.length -= c;
    return ret;
  }
  
  // Copies a specified amount of bytes from the list of buffered data chunks.
  // This function is designed to be inlinable, so please take care when making
  // changes to the function body.
  function copyFromBuffer(n, list) {
    var ret = Buffer.allocUnsafe(n);
    var p = list.head;
    var c = 1;
    p.data.copy(ret);
    n -= p.data.length;
    while (p = p.next) {
      var buf = p.data;
      var nb = n > buf.length ? buf.length : n;
      buf.copy(ret, ret.length - n, 0, nb);
      n -= nb;
      if (n === 0) {
        if (nb === buf.length) {
          ++c;
          if (p.next) list.head = p.next;else list.head = list.tail = null;
        } else {
          list.head = p;
          p.data = buf.slice(nb);
        }
        break;
      }
      ++c;
    }
    list.length -= c;
    return ret;
  }
  
  function endReadable(stream) {
    var state = stream._readableState;
  
    // If we get here before consuming all the bytes, then that is a
    // bug in node.  Should never happen.
    if (state.length > 0) throw new Error('"endReadable()" called on non-empty stream');
  
    if (!state.endEmitted) {
      state.ended = true;
      pna.nextTick(endReadableNT, state, stream);
    }
  }
  
  function endReadableNT(state, stream) {
    // Check that we didn't get one last unshift.
    if (!state.endEmitted && state.length === 0) {
      state.endEmitted = true;
      stream.readable = false;
      stream.emit('end');
    }
  }
  
  function indexOf(xs, x) {
    for (var i = 0, l = xs.length; i < l; i++) {
      if (xs[i] === x) return i;
    }
    return -1;
  }
  }).call(this,require('_process'),typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
  },{"./_stream_duplex":19,"./internal/streams/BufferList":24,"./internal/streams/destroy":25,"./internal/streams/stream":26,"_process":7,"core-util-is":10,"events":4,"inherits":14,"isarray":15,"process-nextick-args":17,"safe-buffer":28,"string_decoder/":30,"util":2}],22:[function(require,module,exports){
  // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  
  // a transform stream is a readable/writable stream where you do
  // something with the data.  Sometimes it's called a "filter",
  // but that's not a great name for it, since that implies a thing where
  // some bits pass through, and others are simply ignored.  (That would
  // be a valid example of a transform, of course.)
  //
  // While the output is causally related to the input, it's not a
  // necessarily symmetric or synchronous transformation.  For example,
  // a zlib stream might take multiple plain-text writes(), and then
  // emit a single compressed chunk some time in the future.
  //
  // Here's how this works:
  //
  // The Transform stream has all the aspects of the readable and writable
  // stream classes.  When you write(chunk), that calls _write(chunk,cb)
  // internally, and returns false if there's a lot of pending writes
  // buffered up.  When you call read(), that calls _read(n) until
  // there's enough pending readable data buffered up.
  //
  // In a transform stream, the written data is placed in a buffer.  When
  // _read(n) is called, it transforms the queued up data, calling the
  // buffered _write cb's as it consumes chunks.  If consuming a single
  // written chunk would result in multiple output chunks, then the first
  // outputted bit calls the readcb, and subsequent chunks just go into
  // the read buffer, and will cause it to emit 'readable' if necessary.
  //
  // This way, back-pressure is actually determined by the reading side,
  // since _read has to be called to start processing a new chunk.  However,
  // a pathological inflate type of transform can cause excessive buffering
  // here.  For example, imagine a stream where every byte of input is
  // interpreted as an integer from 0-255, and then results in that many
  // bytes of output.  Writing the 4 bytes {ff,ff,ff,ff} would result in
  // 1kb of data being output.  In this case, you could write a very small
  // amount of input, and end up with a very large amount of output.  In
  // such a pathological inflating mechanism, there'd be no way to tell
  // the system to stop doing the transform.  A single 4MB write could
  // cause the system to run out of memory.
  //
  // However, even in such a pathological case, only a single written chunk
  // would be consumed, and then the rest would wait (un-transformed) until
  // the results of the previous transformed chunk were consumed.
  
  'use strict';
  
  module.exports = Transform;
  
  var Duplex = require('./_stream_duplex');
  
  /*<replacement>*/
  var util = require('core-util-is');
  util.inherits = require('inherits');
  /*</replacement>*/
  
  util.inherits(Transform, Duplex);
  
  function afterTransform(er, data) {
    var ts = this._transformState;
    ts.transforming = false;
  
    var cb = ts.writecb;
  
    if (!cb) {
      return this.emit('error', new Error('write callback called multiple times'));
    }
  
    ts.writechunk = null;
    ts.writecb = null;
  
    if (data != null) // single equals check for both `null` and `undefined`
      this.push(data);
  
    cb(er);
  
    var rs = this._readableState;
    rs.reading = false;
    if (rs.needReadable || rs.length < rs.highWaterMark) {
      this._read(rs.highWaterMark);
    }
  }
  
  function Transform(options) {
    if (!(this instanceof Transform)) return new Transform(options);
  
    Duplex.call(this, options);
  
    this._transformState = {
      afterTransform: afterTransform.bind(this),
      needTransform: false,
      transforming: false,
      writecb: null,
      writechunk: null,
      writeencoding: null
    };
  
    // start out asking for a readable event once data is transformed.
    this._readableState.needReadable = true;
  
    // we have implemented the _read method, and done the other things
    // that Readable wants before the first _read call, so unset the
    // sync guard flag.
    this._readableState.sync = false;
  
    if (options) {
      if (typeof options.transform === 'function') this._transform = options.transform;
  
      if (typeof options.flush === 'function') this._flush = options.flush;
    }
  
    // When the writable side finishes, then flush out anything remaining.
    this.on('prefinish', prefinish);
  }
  
  function prefinish() {
    var _this = this;
  
    if (typeof this._flush === 'function') {
      this._flush(function (er, data) {
        done(_this, er, data);
      });
    } else {
      done(this, null, null);
    }
  }
  
  Transform.prototype.push = function (chunk, encoding) {
    this._transformState.needTransform = false;
    return Duplex.prototype.push.call(this, chunk, encoding);
  };
  
  // This is the part where you do stuff!
  // override this function in implementation classes.
  // 'chunk' is an input chunk.
  //
  // Call `push(newChunk)` to pass along transformed output
  // to the readable side.  You may call 'push' zero or more times.
  //
  // Call `cb(err)` when you are done with this chunk.  If you pass
  // an error, then that'll put the hurt on the whole operation.  If you
  // never call cb(), then you'll never get another chunk.
  Transform.prototype._transform = function (chunk, encoding, cb) {
    throw new Error('_transform() is not implemented');
  };
  
  Transform.prototype._write = function (chunk, encoding, cb) {
    var ts = this._transformState;
    ts.writecb = cb;
    ts.writechunk = chunk;
    ts.writeencoding = encoding;
    if (!ts.transforming) {
      var rs = this._readableState;
      if (ts.needTransform || rs.needReadable || rs.length < rs.highWaterMark) this._read(rs.highWaterMark);
    }
  };
  
  // Doesn't matter what the args are here.
  // _transform does all the work.
  // That we got here means that the readable side wants more data.
  Transform.prototype._read = function (n) {
    var ts = this._transformState;
  
    if (ts.writechunk !== null && ts.writecb && !ts.transforming) {
      ts.transforming = true;
      this._transform(ts.writechunk, ts.writeencoding, ts.afterTransform);
    } else {
      // mark that we need a transform, so that any data that comes in
      // will get processed, now that we've asked for it.
      ts.needTransform = true;
    }
  };
  
  Transform.prototype._destroy = function (err, cb) {
    var _this2 = this;
  
    Duplex.prototype._destroy.call(this, err, function (err2) {
      cb(err2);
      _this2.emit('close');
    });
  };
  
  function done(stream, er, data) {
    if (er) return stream.emit('error', er);
  
    if (data != null) // single equals check for both `null` and `undefined`
      stream.push(data);
  
    // if there's nothing in the write buffer, then that means
    // that nothing more will ever be provided
    if (stream._writableState.length) throw new Error('Calling transform done when ws.length != 0');
  
    if (stream._transformState.transforming) throw new Error('Calling transform done when still transforming');
  
    return stream.push(null);
  }
  },{"./_stream_duplex":19,"core-util-is":10,"inherits":14}],23:[function(require,module,exports){
  (function (process,global,setImmediate){
  // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  
  // A bit simpler than readable streams.
  // Implement an async ._write(chunk, encoding, cb), and it'll handle all
  // the drain event emission and buffering.
  
  'use strict';
  
  /*<replacement>*/
  
  var pna = require('process-nextick-args');
  /*</replacement>*/
  
  module.exports = Writable;
  
  /* <replacement> */
  function WriteReq(chunk, encoding, cb) {
    this.chunk = chunk;
    this.encoding = encoding;
    this.callback = cb;
    this.next = null;
  }
  
  // It seems a linked list but it is not
  // there will be only 2 of these for each stream
  function CorkedRequest(state) {
    var _this = this;
  
    this.next = null;
    this.entry = null;
    this.finish = function () {
      onCorkedFinish(_this, state);
    };
  }
  /* </replacement> */
  
  /*<replacement>*/
  var asyncWrite = !process.browser && ['v0.10', 'v0.9.'].indexOf(process.version.slice(0, 5)) > -1 ? setImmediate : pna.nextTick;
  /*</replacement>*/
  
  /*<replacement>*/
  var Duplex;
  /*</replacement>*/
  
  Writable.WritableState = WritableState;
  
  /*<replacement>*/
  var util = require('core-util-is');
  util.inherits = require('inherits');
  /*</replacement>*/
  
  /*<replacement>*/
  var internalUtil = {
    deprecate: require('util-deprecate')
  };
  /*</replacement>*/
  
  /*<replacement>*/
  var Stream = require('./internal/streams/stream');
  /*</replacement>*/
  
  /*<replacement>*/
  
  var Buffer = require('safe-buffer').Buffer;
  var OurUint8Array = global.Uint8Array || function () {};
  function _uint8ArrayToBuffer(chunk) {
    return Buffer.from(chunk);
  }
  function _isUint8Array(obj) {
    return Buffer.isBuffer(obj) || obj instanceof OurUint8Array;
  }
  
  /*</replacement>*/
  
  var destroyImpl = require('./internal/streams/destroy');
  
  util.inherits(Writable, Stream);
  
  function nop() {}
  
  function WritableState(options, stream) {
    Duplex = Duplex || require('./_stream_duplex');
  
    options = options || {};
  
    // Duplex streams are both readable and writable, but share
    // the same options object.
    // However, some cases require setting options to different
    // values for the readable and the writable sides of the duplex stream.
    // These options can be provided separately as readableXXX and writableXXX.
    var isDuplex = stream instanceof Duplex;
  
    // object stream flag to indicate whether or not this stream
    // contains buffers or objects.
    this.objectMode = !!options.objectMode;
  
    if (isDuplex) this.objectMode = this.objectMode || !!options.writableObjectMode;
  
    // the point at which write() starts returning false
    // Note: 0 is a valid value, means that we always return false if
    // the entire buffer is not flushed immediately on write()
    var hwm = options.highWaterMark;
    var writableHwm = options.writableHighWaterMark;
    var defaultHwm = this.objectMode ? 16 : 16 * 1024;
  
    if (hwm || hwm === 0) this.highWaterMark = hwm;else if (isDuplex && (writableHwm || writableHwm === 0)) this.highWaterMark = writableHwm;else this.highWaterMark = defaultHwm;
  
    // cast to ints.
    this.highWaterMark = Math.floor(this.highWaterMark);
  
    // if _final has been called
    this.finalCalled = false;
  
    // drain event flag.
    this.needDrain = false;
    // at the start of calling end()
    this.ending = false;
    // when end() has been called, and returned
    this.ended = false;
    // when 'finish' is emitted
    this.finished = false;
  
    // has it been destroyed
    this.destroyed = false;
  
    // should we decode strings into buffers before passing to _write?
    // this is here so that some node-core streams can optimize string
    // handling at a lower level.
    var noDecode = options.decodeStrings === false;
    this.decodeStrings = !noDecode;
  
    // Crypto is kind of old and crusty.  Historically, its default string
    // encoding is 'binary' so we have to make this configurable.
    // Everything else in the universe uses 'utf8', though.
    this.defaultEncoding = options.defaultEncoding || 'utf8';
  
    // not an actual buffer we keep track of, but a measurement
    // of how much we're waiting to get pushed to some underlying
    // socket or file.
    this.length = 0;
  
    // a flag to see when we're in the middle of a write.
    this.writing = false;
  
    // when true all writes will be buffered until .uncork() call
    this.corked = 0;
  
    // a flag to be able to tell if the onwrite cb is called immediately,
    // or on a later tick.  We set this to true at first, because any
    // actions that shouldn't happen until "later" should generally also
    // not happen before the first write call.
    this.sync = true;
  
    // a flag to know if we're processing previously buffered items, which
    // may call the _write() callback in the same tick, so that we don't
    // end up in an overlapped onwrite situation.
    this.bufferProcessing = false;
  
    // the callback that's passed to _write(chunk,cb)
    this.onwrite = function (er) {
      onwrite(stream, er);
    };
  
    // the callback that the user supplies to write(chunk,encoding,cb)
    this.writecb = null;
  
    // the amount that is being written when _write is called.
    this.writelen = 0;
  
    this.bufferedRequest = null;
    this.lastBufferedRequest = null;
  
    // number of pending user-supplied write callbacks
    // this must be 0 before 'finish' can be emitted
    this.pendingcb = 0;
  
    // emit prefinish if the only thing we're waiting for is _write cbs
    // This is relevant for synchronous Transform streams
    this.prefinished = false;
  
    // True if the error was already emitted and should not be thrown again
    this.errorEmitted = false;
  
    // count buffered requests
    this.bufferedRequestCount = 0;
  
    // allocate the first CorkedRequest, there is always
    // one allocated and free to use, and we maintain at most two
    this.corkedRequestsFree = new CorkedRequest(this);
  }
  
  WritableState.prototype.getBuffer = function getBuffer() {
    var current = this.bufferedRequest;
    var out = [];
    while (current) {
      out.push(current);
      current = current.next;
    }
    return out;
  };
  
  (function () {
    try {
      Object.defineProperty(WritableState.prototype, 'buffer', {
        get: internalUtil.deprecate(function () {
          return this.getBuffer();
        }, '_writableState.buffer is deprecated. Use _writableState.getBuffer ' + 'instead.', 'DEP0003')
      });
    } catch (_) {}
  })();
  
  // Test _writableState for inheritance to account for Duplex streams,
  // whose prototype chain only points to Readable.
  var realHasInstance;
  if (typeof Symbol === 'function' && Symbol.hasInstance && typeof Function.prototype[Symbol.hasInstance] === 'function') {
    realHasInstance = Function.prototype[Symbol.hasInstance];
    Object.defineProperty(Writable, Symbol.hasInstance, {
      value: function (object) {
        if (realHasInstance.call(this, object)) return true;
        if (this !== Writable) return false;
  
        return object && object._writableState instanceof WritableState;
      }
    });
  } else {
    realHasInstance = function (object) {
      return object instanceof this;
    };
  }
  
  function Writable(options) {
    Duplex = Duplex || require('./_stream_duplex');
  
    // Writable ctor is applied to Duplexes, too.
    // `realHasInstance` is necessary because using plain `instanceof`
    // would return false, as no `_writableState` property is attached.
  
    // Trying to use the custom `instanceof` for Writable here will also break the
    // Node.js LazyTransform implementation, which has a non-trivial getter for
    // `_writableState` that would lead to infinite recursion.
    if (!realHasInstance.call(Writable, this) && !(this instanceof Duplex)) {
      return new Writable(options);
    }
  
    this._writableState = new WritableState(options, this);
  
    // legacy.
    this.writable = true;
  
    if (options) {
      if (typeof options.write === 'function') this._write = options.write;
  
      if (typeof options.writev === 'function') this._writev = options.writev;
  
      if (typeof options.destroy === 'function') this._destroy = options.destroy;
  
      if (typeof options.final === 'function') this._final = options.final;
    }
  
    Stream.call(this);
  }
  
  // Otherwise people can pipe Writable streams, which is just wrong.
  Writable.prototype.pipe = function () {
    this.emit('error', new Error('Cannot pipe, not readable'));
  };
  
  function writeAfterEnd(stream, cb) {
    var er = new Error('write after end');
    // TODO: defer error events consistently everywhere, not just the cb
    stream.emit('error', er);
    pna.nextTick(cb, er);
  }
  
  // Checks that a user-supplied chunk is valid, especially for the particular
  // mode the stream is in. Currently this means that `null` is never accepted
  // and undefined/non-string values are only allowed in object mode.
  function validChunk(stream, state, chunk, cb) {
    var valid = true;
    var er = false;
  
    if (chunk === null) {
      er = new TypeError('May not write null values to stream');
    } else if (typeof chunk !== 'string' && chunk !== undefined && !state.objectMode) {
      er = new TypeError('Invalid non-string/buffer chunk');
    }
    if (er) {
      stream.emit('error', er);
      pna.nextTick(cb, er);
      valid = false;
    }
    return valid;
  }
  
  Writable.prototype.write = function (chunk, encoding, cb) {
    var state = this._writableState;
    var ret = false;
    var isBuf = !state.objectMode && _isUint8Array(chunk);
  
    if (isBuf && !Buffer.isBuffer(chunk)) {
      chunk = _uint8ArrayToBuffer(chunk);
    }
  
    if (typeof encoding === 'function') {
      cb = encoding;
      encoding = null;
    }
  
    if (isBuf) encoding = 'buffer';else if (!encoding) encoding = state.defaultEncoding;
  
    if (typeof cb !== 'function') cb = nop;
  
    if (state.ended) writeAfterEnd(this, cb);else if (isBuf || validChunk(this, state, chunk, cb)) {
      state.pendingcb++;
      ret = writeOrBuffer(this, state, isBuf, chunk, encoding, cb);
    }
  
    return ret;
  };
  
  Writable.prototype.cork = function () {
    var state = this._writableState;
  
    state.corked++;
  };
  
  Writable.prototype.uncork = function () {
    var state = this._writableState;
  
    if (state.corked) {
      state.corked--;
  
      if (!state.writing && !state.corked && !state.finished && !state.bufferProcessing && state.bufferedRequest) clearBuffer(this, state);
    }
  };
  
  Writable.prototype.setDefaultEncoding = function setDefaultEncoding(encoding) {
    // node::ParseEncoding() requires lower case.
    if (typeof encoding === 'string') encoding = encoding.toLowerCase();
    if (!(['hex', 'utf8', 'utf-8', 'ascii', 'binary', 'base64', 'ucs2', 'ucs-2', 'utf16le', 'utf-16le', 'raw'].indexOf((encoding + '').toLowerCase()) > -1)) throw new TypeError('Unknown encoding: ' + encoding);
    this._writableState.defaultEncoding = encoding;
    return this;
  };
  
  function decodeChunk(state, chunk, encoding) {
    if (!state.objectMode && state.decodeStrings !== false && typeof chunk === 'string') {
      chunk = Buffer.from(chunk, encoding);
    }
    return chunk;
  }
  
  Object.defineProperty(Writable.prototype, 'writableHighWaterMark', {
    // making it explicit this property is not enumerable
    // because otherwise some prototype manipulation in
    // userland will fail
    enumerable: false,
    get: function () {
      return this._writableState.highWaterMark;
    }
  });
  
  // if we're already writing something, then just put this
  // in the queue, and wait our turn.  Otherwise, call _write
  // If we return false, then we need a drain event, so set that flag.
  function writeOrBuffer(stream, state, isBuf, chunk, encoding, cb) {
    if (!isBuf) {
      var newChunk = decodeChunk(state, chunk, encoding);
      if (chunk !== newChunk) {
        isBuf = true;
        encoding = 'buffer';
        chunk = newChunk;
      }
    }
    var len = state.objectMode ? 1 : chunk.length;
  
    state.length += len;
  
    var ret = state.length < state.highWaterMark;
    // we must ensure that previous needDrain will not be reset to false.
    if (!ret) state.needDrain = true;
  
    if (state.writing || state.corked) {
      var last = state.lastBufferedRequest;
      state.lastBufferedRequest = {
        chunk: chunk,
        encoding: encoding,
        isBuf: isBuf,
        callback: cb,
        next: null
      };
      if (last) {
        last.next = state.lastBufferedRequest;
      } else {
        state.bufferedRequest = state.lastBufferedRequest;
      }
      state.bufferedRequestCount += 1;
    } else {
      doWrite(stream, state, false, len, chunk, encoding, cb);
    }
  
    return ret;
  }
  
  function doWrite(stream, state, writev, len, chunk, encoding, cb) {
    state.writelen = len;
    state.writecb = cb;
    state.writing = true;
    state.sync = true;
    if (writev) stream._writev(chunk, state.onwrite);else stream._write(chunk, encoding, state.onwrite);
    state.sync = false;
  }
  
  function onwriteError(stream, state, sync, er, cb) {
    --state.pendingcb;
  
    if (sync) {
      // defer the callback if we are being called synchronously
      // to avoid piling up things on the stack
      pna.nextTick(cb, er);
      // this can emit finish, and it will always happen
      // after error
      pna.nextTick(finishMaybe, stream, state);
      stream._writableState.errorEmitted = true;
      stream.emit('error', er);
    } else {
      // the caller expect this to happen before if
      // it is async
      cb(er);
      stream._writableState.errorEmitted = true;
      stream.emit('error', er);
      // this can emit finish, but finish must
      // always follow error
      finishMaybe(stream, state);
    }
  }
  
  function onwriteStateUpdate(state) {
    state.writing = false;
    state.writecb = null;
    state.length -= state.writelen;
    state.writelen = 0;
  }
  
  function onwrite(stream, er) {
    var state = stream._writableState;
    var sync = state.sync;
    var cb = state.writecb;
  
    onwriteStateUpdate(state);
  
    if (er) onwriteError(stream, state, sync, er, cb);else {
      // Check if we're actually ready to finish, but don't emit yet
      var finished = needFinish(state);
  
      if (!finished && !state.corked && !state.bufferProcessing && state.bufferedRequest) {
        clearBuffer(stream, state);
      }
  
      if (sync) {
        /*<replacement>*/
        asyncWrite(afterWrite, stream, state, finished, cb);
        /*</replacement>*/
      } else {
        afterWrite(stream, state, finished, cb);
      }
    }
  }
  
  function afterWrite(stream, state, finished, cb) {
    if (!finished) onwriteDrain(stream, state);
    state.pendingcb--;
    cb();
    finishMaybe(stream, state);
  }
  
  // Must force callback to be called on nextTick, so that we don't
  // emit 'drain' before the write() consumer gets the 'false' return
  // value, and has a chance to attach a 'drain' listener.
  function onwriteDrain(stream, state) {
    if (state.length === 0 && state.needDrain) {
      state.needDrain = false;
      stream.emit('drain');
    }
  }
  
  // if there's something in the buffer waiting, then process it
  function clearBuffer(stream, state) {
    state.bufferProcessing = true;
    var entry = state.bufferedRequest;
  
    if (stream._writev && entry && entry.next) {
      // Fast case, write everything using _writev()
      var l = state.bufferedRequestCount;
      var buffer = new Array(l);
      var holder = state.corkedRequestsFree;
      holder.entry = entry;
  
      var count = 0;
      var allBuffers = true;
      while (entry) {
        buffer[count] = entry;
        if (!entry.isBuf) allBuffers = false;
        entry = entry.next;
        count += 1;
      }
      buffer.allBuffers = allBuffers;
  
      doWrite(stream, state, true, state.length, buffer, '', holder.finish);
  
      // doWrite is almost always async, defer these to save a bit of time
      // as the hot path ends with doWrite
      state.pendingcb++;
      state.lastBufferedRequest = null;
      if (holder.next) {
        state.corkedRequestsFree = holder.next;
        holder.next = null;
      } else {
        state.corkedRequestsFree = new CorkedRequest(state);
      }
      state.bufferedRequestCount = 0;
    } else {
      // Slow case, write chunks one-by-one
      while (entry) {
        var chunk = entry.chunk;
        var encoding = entry.encoding;
        var cb = entry.callback;
        var len = state.objectMode ? 1 : chunk.length;
  
        doWrite(stream, state, false, len, chunk, encoding, cb);
        entry = entry.next;
        state.bufferedRequestCount--;
        // if we didn't call the onwrite immediately, then
        // it means that we need to wait until it does.
        // also, that means that the chunk and cb are currently
        // being processed, so move the buffer counter past them.
        if (state.writing) {
          break;
        }
      }
  
      if (entry === null) state.lastBufferedRequest = null;
    }
  
    state.bufferedRequest = entry;
    state.bufferProcessing = false;
  }
  
  Writable.prototype._write = function (chunk, encoding, cb) {
    cb(new Error('_write() is not implemented'));
  };
  
  Writable.prototype._writev = null;
  
  Writable.prototype.end = function (chunk, encoding, cb) {
    var state = this._writableState;
  
    if (typeof chunk === 'function') {
      cb = chunk;
      chunk = null;
      encoding = null;
    } else if (typeof encoding === 'function') {
      cb = encoding;
      encoding = null;
    }
  
    if (chunk !== null && chunk !== undefined) this.write(chunk, encoding);
  
    // .end() fully uncorks
    if (state.corked) {
      state.corked = 1;
      this.uncork();
    }
  
    // ignore unnecessary end() calls.
    if (!state.ending && !state.finished) endWritable(this, state, cb);
  };
  
  function needFinish(state) {
    return state.ending && state.length === 0 && state.bufferedRequest === null && !state.finished && !state.writing;
  }
  function callFinal(stream, state) {
    stream._final(function (err) {
      state.pendingcb--;
      if (err) {
        stream.emit('error', err);
      }
      state.prefinished = true;
      stream.emit('prefinish');
      finishMaybe(stream, state);
    });
  }
  function prefinish(stream, state) {
    if (!state.prefinished && !state.finalCalled) {
      if (typeof stream._final === 'function') {
        state.pendingcb++;
        state.finalCalled = true;
        pna.nextTick(callFinal, stream, state);
      } else {
        state.prefinished = true;
        stream.emit('prefinish');
      }
    }
  }
  
  function finishMaybe(stream, state) {
    var need = needFinish(state);
    if (need) {
      prefinish(stream, state);
      if (state.pendingcb === 0) {
        state.finished = true;
        stream.emit('finish');
      }
    }
    return need;
  }
  
  function endWritable(stream, state, cb) {
    state.ending = true;
    finishMaybe(stream, state);
    if (cb) {
      if (state.finished) pna.nextTick(cb);else stream.once('finish', cb);
    }
    state.ended = true;
    stream.writable = false;
  }
  
  function onCorkedFinish(corkReq, state, err) {
    var entry = corkReq.entry;
    corkReq.entry = null;
    while (entry) {
      var cb = entry.callback;
      state.pendingcb--;
      cb(err);
      entry = entry.next;
    }
    if (state.corkedRequestsFree) {
      state.corkedRequestsFree.next = corkReq;
    } else {
      state.corkedRequestsFree = corkReq;
    }
  }
  
  Object.defineProperty(Writable.prototype, 'destroyed', {
    get: function () {
      if (this._writableState === undefined) {
        return false;
      }
      return this._writableState.destroyed;
    },
    set: function (value) {
      // we ignore the value if the stream
      // has not been initialized yet
      if (!this._writableState) {
        return;
      }
  
      // backward compatibility, the user is explicitly
      // managing destroyed
      this._writableState.destroyed = value;
    }
  });
  
  Writable.prototype.destroy = destroyImpl.destroy;
  Writable.prototype._undestroy = destroyImpl.undestroy;
  Writable.prototype._destroy = function (err, cb) {
    this.end();
    cb(err);
  };
  }).call(this,require('_process'),typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {},require("timers").setImmediate)
  },{"./_stream_duplex":19,"./internal/streams/destroy":25,"./internal/streams/stream":26,"_process":7,"core-util-is":10,"inherits":14,"process-nextick-args":17,"safe-buffer":28,"timers":8,"util-deprecate":31}],24:[function(require,module,exports){
  'use strict';
  
  function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
  
  var Buffer = require('safe-buffer').Buffer;
  var util = require('util');
  
  function copyBuffer(src, target, offset) {
    src.copy(target, offset);
  }
  
  module.exports = function () {
    function BufferList() {
      _classCallCheck(this, BufferList);
  
      this.head = null;
      this.tail = null;
      this.length = 0;
    }
  
    BufferList.prototype.push = function push(v) {
      var entry = { data: v, next: null };
      if (this.length > 0) this.tail.next = entry;else this.head = entry;
      this.tail = entry;
      ++this.length;
    };
  
    BufferList.prototype.unshift = function unshift(v) {
      var entry = { data: v, next: this.head };
      if (this.length === 0) this.tail = entry;
      this.head = entry;
      ++this.length;
    };
  
    BufferList.prototype.shift = function shift() {
      if (this.length === 0) return;
      var ret = this.head.data;
      if (this.length === 1) this.head = this.tail = null;else this.head = this.head.next;
      --this.length;
      return ret;
    };
  
    BufferList.prototype.clear = function clear() {
      this.head = this.tail = null;
      this.length = 0;
    };
  
    BufferList.prototype.join = function join(s) {
      if (this.length === 0) return '';
      var p = this.head;
      var ret = '' + p.data;
      while (p = p.next) {
        ret += s + p.data;
      }return ret;
    };
  
    BufferList.prototype.concat = function concat(n) {
      if (this.length === 0) return Buffer.alloc(0);
      if (this.length === 1) return this.head.data;
      var ret = Buffer.allocUnsafe(n >>> 0);
      var p = this.head;
      var i = 0;
      while (p) {
        copyBuffer(p.data, ret, i);
        i += p.data.length;
        p = p.next;
      }
      return ret;
    };
  
    return BufferList;
  }();
  
  if (util && util.inspect && util.inspect.custom) {
    module.exports.prototype[util.inspect.custom] = function () {
      var obj = util.inspect({ length: this.length });
      return this.constructor.name + ' ' + obj;
    };
  }
  },{"safe-buffer":28,"util":2}],25:[function(require,module,exports){
  'use strict';
  
  /*<replacement>*/
  
  var pna = require('process-nextick-args');
  /*</replacement>*/
  
  // undocumented cb() API, needed for core, not for public API
  function destroy(err, cb) {
    var _this = this;
  
    var readableDestroyed = this._readableState && this._readableState.destroyed;
    var writableDestroyed = this._writableState && this._writableState.destroyed;
  
    if (readableDestroyed || writableDestroyed) {
      if (cb) {
        cb(err);
      } else if (err && (!this._writableState || !this._writableState.errorEmitted)) {
        pna.nextTick(emitErrorNT, this, err);
      }
      return this;
    }
  
    // we set destroyed to true before firing error callbacks in order
    // to make it re-entrance safe in case destroy() is called within callbacks
  
    if (this._readableState) {
      this._readableState.destroyed = true;
    }
  
    // if this is a duplex stream mark the writable part as destroyed as well
    if (this._writableState) {
      this._writableState.destroyed = true;
    }
  
    this._destroy(err || null, function (err) {
      if (!cb && err) {
        pna.nextTick(emitErrorNT, _this, err);
        if (_this._writableState) {
          _this._writableState.errorEmitted = true;
        }
      } else if (cb) {
        cb(err);
      }
    });
  
    return this;
  }
  
  function undestroy() {
    if (this._readableState) {
      this._readableState.destroyed = false;
      this._readableState.reading = false;
      this._readableState.ended = false;
      this._readableState.endEmitted = false;
    }
  
    if (this._writableState) {
      this._writableState.destroyed = false;
      this._writableState.ended = false;
      this._writableState.ending = false;
      this._writableState.finished = false;
      this._writableState.errorEmitted = false;
    }
  }
  
  function emitErrorNT(self, err) {
    self.emit('error', err);
  }
  
  module.exports = {
    destroy: destroy,
    undestroy: undestroy
  };
  },{"process-nextick-args":17}],26:[function(require,module,exports){
  module.exports = require('events').EventEmitter;
  
  },{"events":4}],27:[function(require,module,exports){
  exports = module.exports = require('./lib/_stream_readable.js');
  exports.Stream = exports;
  exports.Readable = exports;
  exports.Writable = require('./lib/_stream_writable.js');
  exports.Duplex = require('./lib/_stream_duplex.js');
  exports.Transform = require('./lib/_stream_transform.js');
  exports.PassThrough = require('./lib/_stream_passthrough.js');
  
  },{"./lib/_stream_duplex.js":19,"./lib/_stream_passthrough.js":20,"./lib/_stream_readable.js":21,"./lib/_stream_transform.js":22,"./lib/_stream_writable.js":23}],28:[function(require,module,exports){
  /* eslint-disable node/no-deprecated-api */
  var buffer = require('buffer')
  var Buffer = buffer.Buffer
  
  // alternative to using Object.keys for old browsers
  function copyProps (src, dst) {
    for (var key in src) {
      dst[key] = src[key]
    }
  }
  if (Buffer.from && Buffer.alloc && Buffer.allocUnsafe && Buffer.allocUnsafeSlow) {
    module.exports = buffer
  } else {
    // Copy properties from require('buffer')
    copyProps(buffer, exports)
    exports.Buffer = SafeBuffer
  }
  
  function SafeBuffer (arg, encodingOrOffset, length) {
    return Buffer(arg, encodingOrOffset, length)
  }
  
  // Copy static methods from Buffer
  copyProps(Buffer, SafeBuffer)
  
  SafeBuffer.from = function (arg, encodingOrOffset, length) {
    if (typeof arg === 'number') {
      throw new TypeError('Argument must not be a number')
    }
    return Buffer(arg, encodingOrOffset, length)
  }
  
  SafeBuffer.alloc = function (size, fill, encoding) {
    if (typeof size !== 'number') {
      throw new TypeError('Argument must be a number')
    }
    var buf = Buffer(size)
    if (fill !== undefined) {
      if (typeof encoding === 'string') {
        buf.fill(fill, encoding)
      } else {
        buf.fill(fill)
      }
    } else {
      buf.fill(0)
    }
    return buf
  }
  
  SafeBuffer.allocUnsafe = function (size) {
    if (typeof size !== 'number') {
      throw new TypeError('Argument must be a number')
    }
    return Buffer(size)
  }
  
  SafeBuffer.allocUnsafeSlow = function (size) {
    if (typeof size !== 'number') {
      throw new TypeError('Argument must be a number')
    }
    return buffer.SlowBuffer(size)
  }
  
  },{"buffer":3}],29:[function(require,module,exports){
  (function (Buffer){
  module.exports = Peer
  
  var debug = require('debug')('simple-peer')
  var getBrowserRTC = require('get-browser-rtc')
  var inherits = require('inherits')
  var randombytes = require('randombytes')
  var stream = require('readable-stream')
  
  var MAX_BUFFERED_AMOUNT = 64 * 1024
  var ICECOMPLETE_TIMEOUT = 5 * 1000
  var CHANNEL_CLOSING_TIMEOUT = 5 * 1000
  
  inherits(Peer, stream.Duplex)
  
  /**
   * WebRTC peer connection. Same API as node core `net.Socket`, plus a few extra methods.
   * Duplex stream.
   * @param {Object} opts
   */
  function Peer (opts) {
    var self = this
    if (!(self instanceof Peer)) return new Peer(opts)
  
    self._id = randombytes(4).toString('hex').slice(0, 7)
    self._debug('new peer %o', opts)
  
    opts = Object.assign({
      allowHalfOpen: false
    }, opts)
  
    stream.Duplex.call(self, opts)
  
    self.channelName = opts.initiator
      ? opts.channelName || randombytes(20).toString('hex')
      : null
  
    // Needed by _transformConstraints, so set this early
    self._isChromium = typeof window !== 'undefined' && !!window.webkitRTCPeerConnection
  
    self.initiator = opts.initiator || false
    self.channelConfig = opts.channelConfig || Peer.channelConfig
    self.config = Object.assign({}, Peer.config, opts.config)
    self.constraints = self._transformConstraints(opts.constraints || Peer.constraints)
    self.offerConstraints = self._transformConstraints(opts.offerConstraints || {})
    self.answerConstraints = self._transformConstraints(opts.answerConstraints || {})
    self.sdpTransform = opts.sdpTransform || function (sdp) { return sdp }
    self.streams = opts.streams || (opts.stream ? [opts.stream] : []) // support old "stream" option
    self.trickle = opts.trickle !== undefined ? opts.trickle : true
    self.allowHalfTrickle = opts.allowHalfTrickle !== undefined ? opts.allowHalfTrickle : false
    self.iceCompleteTimeout = opts.iceCompleteTimeout || ICECOMPLETE_TIMEOUT
  
    self.destroyed = false
    self.connected = false
  
    self.remoteAddress = undefined
    self.remoteFamily = undefined
    self.remotePort = undefined
    self.localAddress = undefined
    self.localPort = undefined
  
    self._wrtc = (opts.wrtc && typeof opts.wrtc === 'object')
      ? opts.wrtc
      : getBrowserRTC()
  
    if (!self._wrtc) {
      if (typeof window === 'undefined') {
        throw makeError('No WebRTC support: Specify `opts.wrtc` option in this environment', 'ERR_WEBRTC_SUPPORT')
      } else {
        throw makeError('No WebRTC support: Not a supported browser', 'ERR_WEBRTC_SUPPORT')
      }
    }
  
    self._pcReady = false
    self._channelReady = false
    self._iceComplete = false // ice candidate trickle done (got null candidate)
    self._iceCompleteTimer = null // send an offer/answer anyway after some timeout
    self._channel = null
    self._pendingCandidates = []
  
    self._isNegotiating = !self.initiator // is this peer waiting for negotiation to complete?
    self._batchedNegotiation = false // batch synchronous negotiations
    self._queuedNegotiation = false // is there a queued negotiation request?
    self._sendersAwaitingStable = []
    self._senderMap = new Map()
    self._firstStable = true
    self._closingInterval = null
  
    self._remoteTracks = []
    self._remoteStreams = []
  
    self._chunk = null
    self._cb = null
    self._interval = null
  
    self._pc = new (self._wrtc.RTCPeerConnection)(self.config, self.constraints)
    if (self._isChromium || (self._wrtc && self._wrtc.electronDaemon)) { // HACK: Electron and Chromium need a promise shim
      shimPromiseAPI(self._wrtc.RTCPeerConnection, self._pc)
    }
  
    // We prefer feature detection whenever possible, but sometimes that's not
    // possible for certain implementations.
    self._isReactNativeWebrtc = typeof self._pc._peerConnectionId === 'number'
  
    self._pc.oniceconnectionstatechange = function () {
      self._onIceStateChange()
    }
    self._pc.onicegatheringstatechange = function () {
      self._onIceStateChange()
    }
    self._pc.onsignalingstatechange = function () {
      self._onSignalingStateChange()
    }
    self._pc.onicecandidate = function (event) {
      self._onIceCandidate(event)
    }
  
    // Other spec events, unused by this implementation:
    // - onconnectionstatechange
    // - onicecandidateerror
    // - onfingerprintfailure
    // - onnegotiationneeded
  
    if (self.initiator) {
      self._setupData({
        channel: self._pc.createDataChannel(self.channelName, self.channelConfig)
      })
    } else {
      self._pc.ondatachannel = function (event) {
        self._setupData(event)
      }
    }
  
    if ('addTrack' in self._pc) {
      if (self.streams) {
        self.streams.forEach(function (stream) {
          self.addStream(stream)
        })
      }
      self._pc.ontrack = function (event) {
        self._onTrack(event)
      }
    }
  
    if (self.initiator) {
      self._needsNegotiation()
    }
  
    self._onFinishBound = function () {
      self._onFinish()
    }
    self.once('finish', self._onFinishBound)
  }
  
  Peer.WEBRTC_SUPPORT = !!getBrowserRTC()
  
  /**
   * Expose config, constraints, and data channel config for overriding all Peer
   * instances. Otherwise, just set opts.config, opts.constraints, or opts.channelConfig
   * when constructing a Peer.
   */
  Peer.config = {
    iceServers: [
      {
        urls: 'stun:stun.l.google.com:19302'
      },
      {
        urls: 'stun:global.stun.twilio.com:3478?transport=udp'
      }
    ]
  }
  Peer.constraints = {}
  Peer.channelConfig = {}
  
  Object.defineProperty(Peer.prototype, 'bufferSize', {
    get: function () {
      var self = this
      return (self._channel && self._channel.bufferedAmount) || 0
    }
  })
  
  Peer.prototype.address = function () {
    var self = this
    return { port: self.localPort, family: 'IPv4', address: self.localAddress }
  }
  
  Peer.prototype.signal = function (data) {
    var self = this
    if (self.destroyed) throw makeError('cannot signal after peer is destroyed', 'ERR_SIGNALING')
    if (typeof data === 'string') {
      try {
        data = JSON.parse(data)
      } catch (err) {
        data = {}
      }
    }
    self._debug('signal()')
  
    if (data.renegotiate && self.initiator) {
      self._debug('got request to renegotiate')
      self._needsNegotiation()
    }
    if (data.candidate) {
      if (self._pc.remoteDescription && self._pc.remoteDescription.type) self._addIceCandidate(data.candidate)
      else self._pendingCandidates.push(data.candidate)
    }
    if (data.sdp) {
      self._pc.setRemoteDescription(new (self._wrtc.RTCSessionDescription)(data)).then(function () {
        if (self.destroyed) return
  
        self._pendingCandidates.forEach(function (candidate) {
          self._addIceCandidate(candidate)
        })
        self._pendingCandidates = []
  
        if (self._pc.remoteDescription.type === 'offer') self._createAnswer()
      }).catch(function (err) { self.destroy(makeError(err, 'ERR_SET_REMOTE_DESCRIPTION')) })
    }
    if (!data.sdp && !data.candidate && !data.renegotiate) {
      self.destroy(makeError('signal() called with invalid signal data', 'ERR_SIGNALING'))
    }
  }
  
  Peer.prototype._addIceCandidate = function (candidate) {
    var self = this
    try {
      self._pc.addIceCandidate(
        new self._wrtc.RTCIceCandidate(candidate),
        noop,
        function (err) { self.destroy(makeError(err, 'ERR_ADD_ICE_CANDIDATE')) }
      )
    } catch (err) {
      self.destroy(makeError('error adding candidate: ' + err.message, 'ERR_ADD_ICE_CANDIDATE'))
    }
  }
  
  /**
   * Send text/binary data to the remote peer.
   * @param {ArrayBufferView|ArrayBuffer|Buffer|string|Blob} chunk
   */
  Peer.prototype.send = function (chunk) {
    var self = this
    self._channel.send(chunk)
  }
  
  /**
   * Add a MediaStream to the connection.
   * @param {MediaStream} stream
   */
  Peer.prototype.addStream = function (stream) {
    var self = this
  
    self._debug('addStream()')
  
    stream.getTracks().forEach(function (track) {
      self.addTrack(track, stream)
    })
  }
  
  /**
   * Add a MediaStreamTrack to the connection.
   * @param {MediaStreamTrack} track
   * @param {MediaStream} stream
   */
  Peer.prototype.addTrack = function (track, stream) {
    var self = this
  
    self._debug('addTrack()')
  
    var sender = self._pc.addTrack(track, stream)
    var submap = self._senderMap.get(track) || new Map() // nested Maps map [track, stream] to sender
    submap.set(stream, sender)
    self._senderMap.set(track, submap)
    self._needsNegotiation()
  }
  
  /**
   * Replace a MediaStreamTrack by another in the connection.
   * @param {MediaStreamTrack} oldTrack
   * @param {MediaStreamTrack} newTrack
   * @param {MediaStream} stream
   */
  Peer.prototype.replaceTrack = async function (oldTrack, newTrack, stream) {
    var self = this
  
    self._debug('replaceTrack()')
  
    var submap = self._senderMap.get(oldTrack)
    var sender = submap ? submap.get(stream) : null
    if (!sender) {
      self.destroy(new Error('Cannot replace track that was never added.'))
    }
    if (newTrack) self._senderMap.set(newTrack, submap)
  
    if (sender.replaceTrack != null) {
      await sender.replaceTrack(newTrack)
    } else {
      self.destroy(makeError('replaceTrack is not supported in this browser', 'ERR_UNSUPPORTED_REPLACETRACK'))
    }
  }
  
  /**
   * Remove a MediaStreamTrack from the connection.
   * @param {MediaStreamTrack} track
   * @param {MediaStream} stream
   */
  Peer.prototype.removeTrack = function (track, stream) {
    var self = this
  
    self._debug('removeSender()')
  
    var submap = self._senderMap.get(track)
    var sender = submap ? submap.get(stream) : null
    if (!sender) {
      self.destroy(new Error('Cannot remove track that was never added.'))
    }
    try {
      self._pc.removeTrack(sender)
    } catch (err) {
      if (err.name === 'NS_ERROR_UNEXPECTED') {
        self._sendersAwaitingStable.push(sender) // HACK: Firefox must wait until (signalingState === stable) https://bugzilla.mozilla.org/show_bug.cgi?id=1133874
      } else {
        self.destroy(err)
      }
    }
  }
  
  /**
   * Remove a MediaStream from the connection.
   * @param {MediaStream} stream
   */
  Peer.prototype.removeStream = function (stream) {
    var self = this
  
    self._debug('removeSenders()')
  
    stream.getTracks().forEach(function (track) {
      self.removeTrack(track, stream)
    })
  }
  
  Peer.prototype._needsNegotiation = function () {
    var self = this
  
    self._debug('_needsNegotiation')
    if (self._batchedNegotiation) return // batch synchronous renegotiations
    self._batchedNegotiation = true
    setTimeout(function () {
      self._batchedNegotiation = false
      self._debug('starting batched negotiation')
      self.negotiate()
    }, 0)
  }
  
  Peer.prototype.negotiate = function () {
    var self = this
  
    if (self.initiator) {
      if (self._isNegotiating) {
        self._queuedNegotiation = true
        self._debug('already negotiating, queueing')
      } else {
        self._debug('start negotiation')
        self._createOffer()
      }
    } else {
      if (!self._isNegotiating) {
        self._debug('requesting negotiation from initiator')
        self.emit('signal', { // request initiator to renegotiate
          renegotiate: true
        })
      }
    }
    self._isNegotiating = true
  }
  
  // TODO: Delete this method once readable-stream is updated to contain a default
  // implementation of destroy() that automatically calls _destroy()
  // See: https://github.com/nodejs/readable-stream/issues/283
  Peer.prototype.destroy = function (err) {
    var self = this
    self._destroy(err, function () {})
  }
  
  Peer.prototype._destroy = function (err, cb) {
    var self = this
    if (self.destroyed) return
  
    self._debug('destroy (error: %s)', err && (err.message || err))
  
    self.readable = self.writable = false
  
    if (!self._readableState.ended) self.push(null)
    if (!self._writableState.finished) self.end()
  
    self.destroyed = true
    self.connected = false
    self._pcReady = false
    self._channelReady = false
    self._remoteTracks = null
    self._remoteStreams = null
    self._senderMap = null
  
    clearInterval(self._closingInterval)
    self._closingInterval = null
  
    clearInterval(self._interval)
    self._interval = null
    self._chunk = null
    self._cb = null
  
    if (self._onFinishBound) self.removeListener('finish', self._onFinishBound)
    self._onFinishBound = null
  
    if (self._channel) {
      try {
        self._channel.close()
      } catch (err) {}
  
      self._channel.onmessage = null
      self._channel.onopen = null
      self._channel.onclose = null
      self._channel.onerror = null
    }
    if (self._pc) {
      try {
        self._pc.close()
      } catch (err) {}
  
      self._pc.oniceconnectionstatechange = null
      self._pc.onicegatheringstatechange = null
      self._pc.onsignalingstatechange = null
      self._pc.onicecandidate = null
      if ('addTrack' in self._pc) {
        self._pc.ontrack = null
      }
      self._pc.ondatachannel = null
    }
    self._pc = null
    self._channel = null
  
    if (err) self.emit('error', err)
    self.emit('close')
    cb()
  }
  
  Peer.prototype._setupData = function (event) {
    var self = this
    if (!event.channel) {
      // In some situations `pc.createDataChannel()` returns `undefined` (in wrtc),
      // which is invalid behavior. Handle it gracefully.
      // See: https://github.com/feross/simple-peer/issues/163
      return self.destroy(makeError('Data channel event is missing `channel` property', 'ERR_DATA_CHANNEL'))
    }
  
    self._channel = event.channel
    self._channel.binaryType = 'arraybuffer'
  
    if (typeof self._channel.bufferedAmountLowThreshold === 'number') {
      self._channel.bufferedAmountLowThreshold = MAX_BUFFERED_AMOUNT
    }
  
    self.channelName = self._channel.label
  
    self._channel.onmessage = function (event) {
      self._onChannelMessage(event)
    }
    self._channel.onbufferedamountlow = function () {
      self._onChannelBufferedAmountLow()
    }
    self._channel.onopen = function () {
      self._onChannelOpen()
    }
    self._channel.onclose = function () {
      self._onChannelClose()
    }
    self._channel.onerror = function (err) {
      self.destroy(makeError(err, 'ERR_DATA_CHANNEL'))
    }
  
    // HACK: Chrome will sometimes get stuck in readyState "closing", let's check for this condition
    // https://bugs.chromium.org/p/chromium/issues/detail?id=882743
    var isClosing = false
    self._closingInterval = setInterval(function () { // No "onclosing" event
      if (self._channel && self._channel.readyState === 'closing') {
        if (isClosing) self._onChannelClose() // closing timed out: equivalent to onclose firing
        isClosing = true
      } else {
        isClosing = false
      }
    }, CHANNEL_CLOSING_TIMEOUT)
  }
  
  Peer.prototype._read = function () {}
  
  Peer.prototype._write = function (chunk, encoding, cb) {
    var self = this
    if (self.destroyed) return cb(makeError('cannot write after peer is destroyed', 'ERR_DATA_CHANNEL'))
  
    if (self.connected) {
      try {
        self.send(chunk)
      } catch (err) {
        return self.destroy(makeError(err, 'ERR_DATA_CHANNEL'))
      }
      if (self._channel.bufferedAmount > MAX_BUFFERED_AMOUNT) {
        self._debug('start backpressure: bufferedAmount %d', self._channel.bufferedAmount)
        self._cb = cb
      } else {
        cb(null)
      }
    } else {
      self._debug('write before connect')
      self._chunk = chunk
      self._cb = cb
    }
  }
  
  // When stream finishes writing, close socket. Half open connections are not
  // supported.
  Peer.prototype._onFinish = function () {
    var self = this
    if (self.destroyed) return
  
    if (self.connected) {
      destroySoon()
    } else {
      self.once('connect', destroySoon)
    }
  
    // Wait a bit before destroying so the socket flushes.
    // TODO: is there a more reliable way to accomplish this?
    function destroySoon () {
      setTimeout(function () {
        self.destroy()
      }, 1000)
    }
  }
  
  Peer.prototype._startIceCompleteTimeout = function () {
    debug('started iceComplete timeout')
    var self = this
    if (self.destroyed) return
    if (self._iceCompleteTimer) return
    self._iceCompleteTimer = setTimeout(function () {
      if (!self._iceComplete) {
        self._iceComplete = true
        self.emit('iceTimeout')
        self.emit('_iceComplete')
      }
    }, this.iceCompleteTimeout)
  }
  
  Peer.prototype._createOffer = function () {
    var self = this
    if (self.destroyed) return
  
    self._pc.createOffer(self.offerConstraints).then(function (offer) {
      if (self.destroyed) return
      if (!self.trickle && !self.allowHalfTrickle) offer.sdp = filterTrickle(offer.sdp)
      offer.sdp = self.sdpTransform(offer.sdp)
      self._pc.setLocalDescription(offer).then(onSuccess).catch(onError)
  
      function onSuccess () {
        self._debug('createOffer success')
        if (self.destroyed) return
        if (self.trickle || self._iceComplete) sendOffer()
        else self.once('_iceComplete', sendOffer) // wait for candidates
      }
  
      function onError (err) {
        self.destroy(makeError(err, 'ERR_SET_LOCAL_DESCRIPTION'))
      }
  
      function sendOffer () {
        if (self.destroyed) return
        var signal = self._pc.localDescription || offer
        self._debug('signal')
        self.emit('signal', {
          type: signal.type,
          sdp: signal.sdp
        })
      }
    }).catch(function (err) { self.destroy(makeError(err, 'ERR_CREATE_OFFER')) })
  }
  
  Peer.prototype._createAnswer = function () {
    var self = this
    if (self.destroyed) return
  
    self._pc.createAnswer(self.answerConstraints).then(function (answer) {
      if (self.destroyed) return
      if (!self.trickle && !self.allowHalfTrickle) answer.sdp = filterTrickle(answer.sdp)
      answer.sdp = self.sdpTransform(answer.sdp)
      self._pc.setLocalDescription(answer).then(onSuccess).catch(onError)
  
      function onSuccess () {
        if (self.destroyed) return
        if (self.trickle || self._iceComplete) sendAnswer()
        else self.once('_iceComplete', sendAnswer)
      }
  
      function onError (err) {
        self.destroy(makeError(err, 'ERR_SET_LOCAL_DESCRIPTION'))
      }
  
      function sendAnswer () {
        if (self.destroyed) return
        var signal = self._pc.localDescription || answer
        self._debug('signal')
        self.emit('signal', {
          type: signal.type,
          sdp: signal.sdp
        })
      }
    }).catch(function (err) { self.destroy(makeError(err, 'ERR_CREATE_ANSWER')) })
  }
  
  Peer.prototype._onIceStateChange = function () {
    var self = this
    if (self.destroyed) return
    var iceConnectionState = self._pc.iceConnectionState
    var iceGatheringState = self._pc.iceGatheringState
  
    self._debug(
      'iceStateChange (connection: %s) (gathering: %s)',
      iceConnectionState,
      iceGatheringState
    )
    self.emit('iceStateChange', iceConnectionState, iceGatheringState)
  
    if (iceConnectionState === 'connected' || iceConnectionState === 'completed') {
      self._pcReady = true
      self._maybeReady()
    }
    if (iceConnectionState === 'failed') {
      self.destroy(makeError('Ice connection failed.', 'ERR_ICE_CONNECTION_FAILURE'))
    }
    if (iceConnectionState === 'closed') {
      self.destroy(new Error('Ice connection closed.'))
    }
  }
  
  Peer.prototype.getStats = function (cb) {
    var self = this
  
    // Promise-based getStats() (standard)
    if (self._pc.getStats.length === 0) {
      self._pc.getStats().then(function (res) {
        var reports = []
        res.forEach(function (report) {
          reports.push(report)
        })
        cb(null, reports)
      }, function (err) { cb(err) })
  
    // Two-parameter callback-based getStats() (deprecated, former standard)
    } else if (self._isReactNativeWebrtc) {
      self._pc.getStats(null, function (res) {
        var reports = []
        res.forEach(function (report) {
          reports.push(report)
        })
        cb(null, reports)
      }, function (err) { cb(err) })
  
    // Single-parameter callback-based getStats() (non-standard)
    } else if (self._pc.getStats.length > 0) {
      self._pc.getStats(function (res) {
        // If we destroy connection in `connect` callback this code might happen to run when actual connection is already closed
        if (self.destroyed) return
  
        var reports = []
        res.result().forEach(function (result) {
          var report = {}
          result.names().forEach(function (name) {
            report[name] = result.stat(name)
          })
          report.id = result.id
          report.type = result.type
          report.timestamp = result.timestamp
          reports.push(report)
        })
        cb(null, reports)
      }, function (err) { cb(err) })
  
    // Unknown browser, skip getStats() since it's anyone's guess which style of
    // getStats() they implement.
    } else {
      cb(null, [])
    }
  }
  
  Peer.prototype._maybeReady = function () {
    var self = this
    self._debug('maybeReady pc %s channel %s', self._pcReady, self._channelReady)
    if (self.connected || self._connecting || !self._pcReady || !self._channelReady) return
  
    self._connecting = true
  
    // HACK: We can't rely on order here, for details see https://github.com/js-platform/node-webrtc/issues/339
    function findCandidatePair () {
      if (self.destroyed) return
  
      self.getStats(function (err, items) {
        if (self.destroyed) return
  
        // Treat getStats error as non-fatal. It's not essential.
        if (err) items = []
  
        var remoteCandidates = {}
        var localCandidates = {}
        var candidatePairs = {}
        var foundSelectedCandidatePair = false
  
        items.forEach(function (item) {
          // TODO: Once all browsers support the hyphenated stats report types, remove
          // the non-hypenated ones
          if (item.type === 'remotecandidate' || item.type === 'remote-candidate') {
            remoteCandidates[item.id] = item
          }
          if (item.type === 'localcandidate' || item.type === 'local-candidate') {
            localCandidates[item.id] = item
          }
          if (item.type === 'candidatepair' || item.type === 'candidate-pair') {
            candidatePairs[item.id] = item
          }
        })
  
        items.forEach(function (item) {
          // Spec-compliant
          if (item.type === 'transport' && item.selectedCandidatePairId) {
            setSelectedCandidatePair(candidatePairs[item.selectedCandidatePairId])
          }
  
          // Old implementations
          if (
            (item.type === 'googCandidatePair' && item.googActiveConnection === 'true') ||
            ((item.type === 'candidatepair' || item.type === 'candidate-pair') && item.selected)
          ) {
            setSelectedCandidatePair(item)
          }
        })
  
        function setSelectedCandidatePair (selectedCandidatePair) {
          foundSelectedCandidatePair = true
  
          var local = localCandidates[selectedCandidatePair.localCandidateId]
  
          if (local && local.ip) {
            // Spec
            self.localAddress = local.ip
            self.localPort = Number(local.port)
          } else if (local && local.ipAddress) {
            // Firefox
            self.localAddress = local.ipAddress
            self.localPort = Number(local.portNumber)
          } else if (typeof selectedCandidatePair.googLocalAddress === 'string') {
            // TODO: remove this once Chrome 58 is released
            local = selectedCandidatePair.googLocalAddress.split(':')
            self.localAddress = local[0]
            self.localPort = Number(local[1])
          }
  
          var remote = remoteCandidates[selectedCandidatePair.remoteCandidateId]
  
          if (remote && remote.ip) {
            // Spec
            self.remoteAddress = remote.ip
            self.remotePort = Number(remote.port)
          } else if (remote && remote.ipAddress) {
            // Firefox
            self.remoteAddress = remote.ipAddress
            self.remotePort = Number(remote.portNumber)
          } else if (typeof selectedCandidatePair.googRemoteAddress === 'string') {
            // TODO: remove this once Chrome 58 is released
            remote = selectedCandidatePair.googRemoteAddress.split(':')
            self.remoteAddress = remote[0]
            self.remotePort = Number(remote[1])
          }
          self.remoteFamily = 'IPv4'
  
          self._debug(
            'connect local: %s:%s remote: %s:%s',
            self.localAddress, self.localPort, self.remoteAddress, self.remotePort
          )
        }
  
        // Ignore candidate pair selection in browsers like Safari 11 that do not have any local or remote candidates
        // But wait until at least 1 candidate pair is available
        if (!foundSelectedCandidatePair && (!Object.keys(candidatePairs).length || Object.keys(localCandidates).length)) {
          setTimeout(findCandidatePair, 100)
          return
        } else {
          self._connecting = false
          self.connected = true
        }
  
        if (self._chunk) {
          try {
            self.send(self._chunk)
          } catch (err) {
            return self.destroy(makeError(err, 'ERR_DATA_CHANNEL'))
          }
          self._chunk = null
          self._debug('sent chunk from "write before connect"')
  
          var cb = self._cb
          self._cb = null
          cb(null)
        }
  
        // If `bufferedAmountLowThreshold` and 'onbufferedamountlow' are unsupported,
        // fallback to using setInterval to implement backpressure.
        if (typeof self._channel.bufferedAmountLowThreshold !== 'number') {
          self._interval = setInterval(function () { self._onInterval() }, 150)
          if (self._interval.unref) self._interval.unref()
        }
  
        self._debug('connect')
        self.emit('connect')
      })
    }
    findCandidatePair()
  }
  
  Peer.prototype._onInterval = function () {
    var self = this
    if (!self._cb || !self._channel || self._channel.bufferedAmount > MAX_BUFFERED_AMOUNT) {
      return
    }
    self._onChannelBufferedAmountLow()
  }
  
  Peer.prototype._onSignalingStateChange = function () {
    var self = this
    if (self.destroyed) return
  
    if (self._pc.signalingState === 'stable' && !self._firstStable) {
      self._isNegotiating = false
  
      // HACK: Firefox doesn't yet support removing tracks when signalingState !== 'stable'
      self._debug('flushing sender queue', self._sendersAwaitingStable)
      self._sendersAwaitingStable.forEach(function (sender) {
        self._pc.removeTrack(sender)
        self._queuedNegotiation = true
      })
      self._sendersAwaitingStable = []
  
      if (self._queuedNegotiation) {
        self._debug('flushing negotiation queue')
        self._queuedNegotiation = false
        self._needsNegotiation() // negotiate again
      }
  
      self._debug('negotiate')
      self.emit('negotiate')
    }
    self._firstStable = false
  
    self._debug('signalingStateChange %s', self._pc.signalingState)
    self.emit('signalingStateChange', self._pc.signalingState)
  }
  
  Peer.prototype._onIceCandidate = function (event) {
    var self = this
    if (self.destroyed) return
    if (event.candidate && self.trickle) {
      self.emit('signal', {
        candidate: {
          candidate: event.candidate.candidate,
          sdpMLineIndex: event.candidate.sdpMLineIndex,
          sdpMid: event.candidate.sdpMid
        }
      })
    } else if (!event.candidate && !self._iceComplete) {
      self._iceComplete = true
      self.emit('_iceComplete')
    }
    // as soon as we've received one valid candidate start timeout
    if (event.candidate) {
      self._startIceCompleteTimeout()
    }
  }
  
  Peer.prototype._onChannelMessage = function (event) {
    var self = this
    if (self.destroyed) return
    var data = event.data
    if (data instanceof ArrayBuffer) data = Buffer.from(data)
    self.push(data)
  }
  
  Peer.prototype._onChannelBufferedAmountLow = function () {
    var self = this
    if (self.destroyed || !self._cb) return
    self._debug('ending backpressure: bufferedAmount %d', self._channel.bufferedAmount)
    var cb = self._cb
    self._cb = null
    cb(null)
  }
  
  Peer.prototype._onChannelOpen = function () {
    var self = this
    if (self.connected || self.destroyed) return
    self._debug('on channel open')
    self._channelReady = true
    self._maybeReady()
  }
  
  Peer.prototype._onChannelClose = function () {
    var self = this
    if (self.destroyed) return
    self._debug('on channel close')
    self.destroy()
  }
  
  Peer.prototype._onTrack = function (event) {
    var self = this
    if (self.destroyed) return
  
    event.streams.forEach(function (eventStream) {
      self._debug('on track')
      self.emit('track', event.track, eventStream)
  
      self._remoteTracks.push({
        track: event.track,
        stream: eventStream
      })
  
      if (self._remoteStreams.some(function (remoteStream) {
        return remoteStream.id === eventStream.id
      })) return // Only fire one 'stream' event, even though there may be multiple tracks per stream
  
      self._remoteStreams.push(eventStream)
      setTimeout(function () {
        self.emit('stream', eventStream) // ensure all tracks have been added
      }, 0)
    })
  }
  
  Peer.prototype.setConstraints = function (constraints) {
    var self = this
    if (self.initiator) {
      self.offerConstraints = self._transformConstraints(constraints)
    } else {
      self.answerConstraints = self._transformConstraints(constraints)
    }
  }
  
  Peer.prototype._debug = function () {
    var self = this
    var args = [].slice.call(arguments)
    args[0] = '[' + self._id + '] ' + args[0]
    debug.apply(null, args)
  }
  
  // Transform constraints objects into the new format (unless Chromium)
  // TODO: This can be removed when Chromium supports the new format
  Peer.prototype._transformConstraints = function (constraints) {
    var self = this
  
    if (Object.keys(constraints).length === 0) {
      return constraints
    }
  
    if ((constraints.mandatory || constraints.optional) && !self._isChromium) {
      // convert to new format
  
      // Merge mandatory and optional objects, prioritizing mandatory
      var newConstraints = Object.assign({}, constraints.optional, constraints.mandatory)
  
      // fix casing
      if (newConstraints.OfferToReceiveVideo !== undefined) {
        newConstraints.offerToReceiveVideo = newConstraints.OfferToReceiveVideo
        delete newConstraints['OfferToReceiveVideo']
      }
  
      if (newConstraints.OfferToReceiveAudio !== undefined) {
        newConstraints.offerToReceiveAudio = newConstraints.OfferToReceiveAudio
        delete newConstraints['OfferToReceiveAudio']
      }
  
      return newConstraints
    } else if (!constraints.mandatory && !constraints.optional && self._isChromium) {
      // convert to old format
  
      // fix casing
      if (constraints.offerToReceiveVideo !== undefined) {
        constraints.OfferToReceiveVideo = constraints.offerToReceiveVideo
        delete constraints['offerToReceiveVideo']
      }
  
      if (constraints.offerToReceiveAudio !== undefined) {
        constraints.OfferToReceiveAudio = constraints.offerToReceiveAudio
        delete constraints['offerToReceiveAudio']
      }
  
      return {
        mandatory: constraints // NOTE: All constraints are upgraded to mandatory
      }
    }
  
    return constraints
  }
  
  // HACK: Minimal shim to force Chrome and WRTC to use their more reliable callback API
  function shimPromiseAPI (RTCPeerConnection, pc) {
    pc.createOffer = function (constraints) {
      return new Promise((resolve, reject) => {
        RTCPeerConnection.prototype.createOffer.call(this, resolve, reject, constraints)
      })
    }
    pc.createAnswer = function (constraints) {
      return new Promise((resolve, reject) => {
        RTCPeerConnection.prototype.createAnswer.call(this, resolve, reject, constraints)
      })
    }
    pc.setLocalDescription = function (description) {
      return new Promise((resolve, reject) => {
        RTCPeerConnection.prototype.setLocalDescription.call(this, description, resolve, reject)
      })
    }
    pc.setRemoteDescription = function (description) {
      return new Promise((resolve, reject) => {
        RTCPeerConnection.prototype.setRemoteDescription.call(this, description, resolve, reject)
      })
    }
  }
  
  // HACK: Filter trickle lines when trickle is disabled #354
  function filterTrickle (sdp) {
    return sdp.replace(/a=ice-options:trickle\s\n/g, '')
  }
  
  function makeError (message, code) {
    var err = new Error(message)
    err.code = code
    return err
  }
  
  function noop () {}
  
  }).call(this,require("buffer").Buffer)
  },{"buffer":3,"debug":11,"get-browser-rtc":13,"inherits":14,"randombytes":18,"readable-stream":27}],30:[function(require,module,exports){
  // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  
  'use strict';
  
  /*<replacement>*/
  
  var Buffer = require('safe-buffer').Buffer;
  /*</replacement>*/
  
  var isEncoding = Buffer.isEncoding || function (encoding) {
    encoding = '' + encoding;
    switch (encoding && encoding.toLowerCase()) {
      case 'hex':case 'utf8':case 'utf-8':case 'ascii':case 'binary':case 'base64':case 'ucs2':case 'ucs-2':case 'utf16le':case 'utf-16le':case 'raw':
        return true;
      default:
        return false;
    }
  };
  
  function _normalizeEncoding(enc) {
    if (!enc) return 'utf8';
    var retried;
    while (true) {
      switch (enc) {
        case 'utf8':
        case 'utf-8':
          return 'utf8';
        case 'ucs2':
        case 'ucs-2':
        case 'utf16le':
        case 'utf-16le':
          return 'utf16le';
        case 'latin1':
        case 'binary':
          return 'latin1';
        case 'base64':
        case 'ascii':
        case 'hex':
          return enc;
        default:
          if (retried) return; // undefined
          enc = ('' + enc).toLowerCase();
          retried = true;
      }
    }
  };
  
  // Do not cache `Buffer.isEncoding` when checking encoding names as some
  // modules monkey-patch it to support additional encodings
  function normalizeEncoding(enc) {
    var nenc = _normalizeEncoding(enc);
    if (typeof nenc !== 'string' && (Buffer.isEncoding === isEncoding || !isEncoding(enc))) throw new Error('Unknown encoding: ' + enc);
    return nenc || enc;
  }
  
  // StringDecoder provides an interface for efficiently splitting a series of
  // buffers into a series of JS strings without breaking apart multi-byte
  // characters.
  exports.StringDecoder = StringDecoder;
  function StringDecoder(encoding) {
    this.encoding = normalizeEncoding(encoding);
    var nb;
    switch (this.encoding) {
      case 'utf16le':
        this.text = utf16Text;
        this.end = utf16End;
        nb = 4;
        break;
      case 'utf8':
        this.fillLast = utf8FillLast;
        nb = 4;
        break;
      case 'base64':
        this.text = base64Text;
        this.end = base64End;
        nb = 3;
        break;
      default:
        this.write = simpleWrite;
        this.end = simpleEnd;
        return;
    }
    this.lastNeed = 0;
    this.lastTotal = 0;
    this.lastChar = Buffer.allocUnsafe(nb);
  }
  
  StringDecoder.prototype.write = function (buf) {
    if (buf.length === 0) return '';
    var r;
    var i;
    if (this.lastNeed) {
      r = this.fillLast(buf);
      if (r === undefined) return '';
      i = this.lastNeed;
      this.lastNeed = 0;
    } else {
      i = 0;
    }
    if (i < buf.length) return r ? r + this.text(buf, i) : this.text(buf, i);
    return r || '';
  };
  
  StringDecoder.prototype.end = utf8End;
  
  // Returns only complete characters in a Buffer
  StringDecoder.prototype.text = utf8Text;
  
  // Attempts to complete a partial non-UTF-8 character using bytes from a Buffer
  StringDecoder.prototype.fillLast = function (buf) {
    if (this.lastNeed <= buf.length) {
      buf.copy(this.lastChar, this.lastTotal - this.lastNeed, 0, this.lastNeed);
      return this.lastChar.toString(this.encoding, 0, this.lastTotal);
    }
    buf.copy(this.lastChar, this.lastTotal - this.lastNeed, 0, buf.length);
    this.lastNeed -= buf.length;
  };
  
  // Checks the type of a UTF-8 byte, whether it's ASCII, a leading byte, or a
  // continuation byte. If an invalid byte is detected, -2 is returned.
  function utf8CheckByte(byte) {
    if (byte <= 0x7F) return 0;else if (byte >> 5 === 0x06) return 2;else if (byte >> 4 === 0x0E) return 3;else if (byte >> 3 === 0x1E) return 4;
    return byte >> 6 === 0x02 ? -1 : -2;
  }
  
  // Checks at most 3 bytes at the end of a Buffer in order to detect an
  // incomplete multi-byte UTF-8 character. The total number of bytes (2, 3, or 4)
  // needed to complete the UTF-8 character (if applicable) are returned.
  function utf8CheckIncomplete(self, buf, i) {
    var j = buf.length - 1;
    if (j < i) return 0;
    var nb = utf8CheckByte(buf[j]);
    if (nb >= 0) {
      if (nb > 0) self.lastNeed = nb - 1;
      return nb;
    }
    if (--j < i || nb === -2) return 0;
    nb = utf8CheckByte(buf[j]);
    if (nb >= 0) {
      if (nb > 0) self.lastNeed = nb - 2;
      return nb;
    }
    if (--j < i || nb === -2) return 0;
    nb = utf8CheckByte(buf[j]);
    if (nb >= 0) {
      if (nb > 0) {
        if (nb === 2) nb = 0;else self.lastNeed = nb - 3;
      }
      return nb;
    }
    return 0;
  }
  
  // Validates as many continuation bytes for a multi-byte UTF-8 character as
  // needed or are available. If we see a non-continuation byte where we expect
  // one, we "replace" the validated continuation bytes we've seen so far with
  // a single UTF-8 replacement character ('\ufffd'), to match v8's UTF-8 decoding
  // behavior. The continuation byte check is included three times in the case
  // where all of the continuation bytes for a character exist in the same buffer.
  // It is also done this way as a slight performance increase instead of using a
  // loop.
  function utf8CheckExtraBytes(self, buf, p) {
    if ((buf[0] & 0xC0) !== 0x80) {
      self.lastNeed = 0;
      return '\ufffd';
    }
    if (self.lastNeed > 1 && buf.length > 1) {
      if ((buf[1] & 0xC0) !== 0x80) {
        self.lastNeed = 1;
        return '\ufffd';
      }
      if (self.lastNeed > 2 && buf.length > 2) {
        if ((buf[2] & 0xC0) !== 0x80) {
          self.lastNeed = 2;
          return '\ufffd';
        }
      }
    }
  }
  
  // Attempts to complete a multi-byte UTF-8 character using bytes from a Buffer.
  function utf8FillLast(buf) {
    var p = this.lastTotal - this.lastNeed;
    var r = utf8CheckExtraBytes(this, buf, p);
    if (r !== undefined) return r;
    if (this.lastNeed <= buf.length) {
      buf.copy(this.lastChar, p, 0, this.lastNeed);
      return this.lastChar.toString(this.encoding, 0, this.lastTotal);
    }
    buf.copy(this.lastChar, p, 0, buf.length);
    this.lastNeed -= buf.length;
  }
  
  // Returns all complete UTF-8 characters in a Buffer. If the Buffer ended on a
  // partial character, the character's bytes are buffered until the required
  // number of bytes are available.
  function utf8Text(buf, i) {
    var total = utf8CheckIncomplete(this, buf, i);
    if (!this.lastNeed) return buf.toString('utf8', i);
    this.lastTotal = total;
    var end = buf.length - (total - this.lastNeed);
    buf.copy(this.lastChar, 0, end);
    return buf.toString('utf8', i, end);
  }
  
  // For UTF-8, a replacement character is added when ending on a partial
  // character.
  function utf8End(buf) {
    var r = buf && buf.length ? this.write(buf) : '';
    if (this.lastNeed) return r + '\ufffd';
    return r;
  }
  
  // UTF-16LE typically needs two bytes per character, but even if we have an even
  // number of bytes available, we need to check if we end on a leading/high
  // surrogate. In that case, we need to wait for the next two bytes in order to
  // decode the last character properly.
  function utf16Text(buf, i) {
    if ((buf.length - i) % 2 === 0) {
      var r = buf.toString('utf16le', i);
      if (r) {
        var c = r.charCodeAt(r.length - 1);
        if (c >= 0xD800 && c <= 0xDBFF) {
          this.lastNeed = 2;
          this.lastTotal = 4;
          this.lastChar[0] = buf[buf.length - 2];
          this.lastChar[1] = buf[buf.length - 1];
          return r.slice(0, -1);
        }
      }
      return r;
    }
    this.lastNeed = 1;
    this.lastTotal = 2;
    this.lastChar[0] = buf[buf.length - 1];
    return buf.toString('utf16le', i, buf.length - 1);
  }
  
  // For UTF-16LE we do not explicitly append special replacement characters if we
  // end on a partial character, we simply let v8 handle that.
  function utf16End(buf) {
    var r = buf && buf.length ? this.write(buf) : '';
    if (this.lastNeed) {
      var end = this.lastTotal - this.lastNeed;
      return r + this.lastChar.toString('utf16le', 0, end);
    }
    return r;
  }
  
  function base64Text(buf, i) {
    var n = (buf.length - i) % 3;
    if (n === 0) return buf.toString('base64', i);
    this.lastNeed = 3 - n;
    this.lastTotal = 3;
    if (n === 1) {
      this.lastChar[0] = buf[buf.length - 1];
    } else {
      this.lastChar[0] = buf[buf.length - 2];
      this.lastChar[1] = buf[buf.length - 1];
    }
    return buf.toString('base64', i, buf.length - n);
  }
  
  function base64End(buf) {
    var r = buf && buf.length ? this.write(buf) : '';
    if (this.lastNeed) return r + this.lastChar.toString('base64', 0, 3 - this.lastNeed);
    return r;
  }
  
  // Pass bytes on through for single-byte encodings (e.g. ascii, latin1, hex)
  function simpleWrite(buf) {
    return buf.toString(this.encoding);
  }
  
  function simpleEnd(buf) {
    return buf && buf.length ? this.write(buf) : '';
  }
  },{"safe-buffer":28}],31:[function(require,module,exports){
  (function (global){
  
  /**
   * Module exports.
   */
  
  module.exports = deprecate;
  
  /**
   * Mark that a method should not be used.
   * Returns a modified function which warns once by default.
   *
   * If `localStorage.noDeprecation = true` is set, then it is a no-op.
   *
   * If `localStorage.throwDeprecation = true` is set, then deprecated functions
   * will throw an Error when invoked.
   *
   * If `localStorage.traceDeprecation = true` is set, then deprecated functions
   * will invoke `console.trace()` instead of `console.error()`.
   *
   * @param {Function} fn - the function to deprecate
   * @param {String} msg - the string to print to the console when `fn` is invoked
   * @returns {Function} a new "deprecated" version of `fn`
   * @api public
   */
  
  function deprecate (fn, msg) {
    if (config('noDeprecation')) {
      return fn;
    }
  
    var warned = false;
    function deprecated() {
      if (!warned) {
        if (config('throwDeprecation')) {
          throw new Error(msg);
        } else if (config('traceDeprecation')) {
          console.trace(msg);
        } else {
          console.warn(msg);
        }
        warned = true;
      }
      return fn.apply(this, arguments);
    }
  
    return deprecated;
  }
  
  /**
   * Checks `localStorage` for boolean values for the given `name`.
   *
   * @param {String} name
   * @returns {Boolean}
   * @api private
   */
  
  function config (name) {
    // accessing global.localStorage can trigger a DOMException in sandboxed iframes
    try {
      if (!global.localStorage) return false;
    } catch (_) {
      return false;
    }
    var val = global.localStorage[name];
    if (null == val) return false;
    return String(val).toLowerCase() === 'true';
  }
  
  }).call(this,typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
  },{}]},{},[9]);
  