text: /*!
   * https://github.com/paulmillr/es6-shim
   * @license es6-shim Copyright 2013-2016 by Paul Miller (http://paulmillr.com)
   *   and contributors,  MIT License
   * es6-shim: v0.35.3
   * see https://github.com/paulmillr/es6-shim/blob/0.35.3/LICENSE
   * Details and documentation:
   * https://github.com/paulmillr/es6-shim/
   */
  
  // UMD (Universal Module Definition)
  // see https://github.com/umdjs/umd/blob/master/returnExports.js
  (function (root, factory) {
      /*global define, module, exports */
      if (typeof define === 'function' && define.amd) {
          // AMD. Register as an anonymous module.
          define(factory);
      } else if (typeof exports === 'object') {
          // Node. Does not work with strict CommonJS, but
          // only CommonJS-like environments that support module.exports,
          // like Node.
          module.exports = factory();
      } else {
          // Browser globals (root is window)
          root.returnExports = factory();
      }
  }(this, function () {
      'use strict';
  
      var _apply = Function.call.bind(Function.apply);
      var _call = Function.call.bind(Function.call);
      var isArray = Array.isArray;
      var keys = Object.keys;
  
      var not = function notThunker(func) {
          return function notThunk() {
              return !_apply(func, this, arguments);
          };
      };
      var throwsError = function (func) {
          try {
              func();
              return false;
          } catch (e) {
              return true;
          }
      };
      var valueOrFalseIfThrows = function valueOrFalseIfThrows(func) {
          try {
              return func();
          } catch (e) {
              return false;
          }
      };
  
      var isCallableWithoutNew = not(throwsError);
      var arePropertyDescriptorsSupported = function () {
          // if Object.defineProperty exists but throws, it's IE 8
          return !throwsError(function () {
              Object.defineProperty({}, 'x', { get: function () {} });
          });
      };
      var supportsDescriptors = !!Object.defineProperty && arePropertyDescriptorsSupported();
      var functionsHaveNames = (function foo() {}).name === 'foo'; // eslint-disable-line no-extra-parens
  
      var _forEach = Function.call.bind(Array.prototype.forEach);
      var _reduce = Function.call.bind(Array.prototype.reduce);
      var _filter = Function.call.bind(Array.prototype.filter);
      var _some = Function.call.bind(Array.prototype.some);
  
      var defineProperty = function (object, name, value, force) {
          if (!force && name in object) { return; }
          if (supportsDescriptors) {
              Object.defineProperty(object, name, {
                  configurable: true,
                  enumerable: false,
                  writable: true,
                  value: value
              });
          } else {
              object[name] = value;
          }
      };
  
      // Define configurable, writable and non-enumerable props
      // if they don’t exist.
      var defineProperties = function (object, map, forceOverride) {
          _forEach(keys(map), function (name) {
              var method = map[name];
              defineProperty(object, name, method, !!forceOverride);
          });
      };
  
      var _toString = Function.call.bind(Object.prototype.toString);
      var isCallable = typeof /abc/ === 'function' ? function IsCallableSlow(x) {
          // Some old browsers (IE, FF) say that typeof /abc/ === 'function'
          return typeof x === 'function' && _toString(x) === '[object Function]';
      } : function IsCallableFast(x) { return typeof x === 'function'; };
  
      var Value = {
          getter: function (object, name, getter) {
              if (!supportsDescriptors) {
                  throw new TypeError('getters require true ES5 support');
              }
              Object.defineProperty(object, name, {
                  configurable: true,
                  enumerable: false,
                  get: getter
              });
          },
          proxy: function (originalObject, key, targetObject) {
              if (!supportsDescriptors) {
                  throw new TypeError('getters require true ES5 support');
              }
              var originalDescriptor = Object.getOwnPropertyDescriptor(originalObject, key);
              Object.defineProperty(targetObject, key, {
                  configurable: originalDescriptor.configurable,
                  enumerable: originalDescriptor.enumerable,
                  get: function getKey() { return originalObject[key]; },
                  set: function setKey(value) { originalObject[key] = value; }
              });
          },
          redefine: function (object, property, newValue) {
              if (supportsDescriptors) {
                  var descriptor = Object.getOwnPropertyDescriptor(object, property);
                  descriptor.value = newValue;
                  Object.defineProperty(object, property, descriptor);
              } else {
                  object[property] = newValue;
              }
          },
          defineByDescriptor: function (object, property, descriptor) {
              if (supportsDescriptors) {
                  Object.defineProperty(object, property, descriptor);
              } else if ('value' in descriptor) {
                  object[property] = descriptor.value;
              }
          },
          preserveToString: function (target, source) {
              if (source && isCallable(source.toString)) {
                  defineProperty(target, 'toString', source.toString.bind(source), true);
              }
          }
      };
  
      // Simple shim for Object.create on ES3 browsers
      // (unlike real shim, no attempt to support `prototype === null`)
      var create = Object.create || function (prototype, properties) {
              var Prototype = function Prototype() {};
              Prototype.prototype = prototype;
              var object = new Prototype();
              if (typeof properties !== 'undefined') {
                  keys(properties).forEach(function (key) {
                      Value.defineByDescriptor(object, key, properties[key]);
                  });
              }
              return object;
          };
  
      var supportsSubclassing = function (C, f) {
          if (!Object.setPrototypeOf) { return false; /* skip test on IE < 11 */ }
          return valueOrFalseIfThrows(function () {
              var Sub = function Subclass(arg) {
                  var o = new C(arg);
                  Object.setPrototypeOf(o, Subclass.prototype);
                  return o;
              };
              Object.setPrototypeOf(Sub, C);
              Sub.prototype = create(C.prototype, {
                  constructor: { value: Sub }
              });
              return f(Sub);
          });
      };
  
      var getGlobal = function () {
          /* global self, window, global */
          // the only reliable means to get the global object is
          // `Function('return this')()`
          // However, this causes CSP violations in Chrome apps.
          if (typeof self !== 'undefined') { return self; }
          if (typeof window !== 'undefined') { return window; }
          if (typeof global !== 'undefined') { return global; }
          throw new Error('unable to locate global object');
      };
  
      var globals = getGlobal();
      var globalIsFinite = globals.isFinite;
      var _indexOf = Function.call.bind(String.prototype.indexOf);
      var _arrayIndexOfApply = Function.apply.bind(Array.prototype.indexOf);
      var _concat = Function.call.bind(Array.prototype.concat);
      // var _sort = Function.call.bind(Array.prototype.sort);
      var _strSlice = Function.call.bind(String.prototype.slice);
      var _push = Function.call.bind(Array.prototype.push);
      var _pushApply = Function.apply.bind(Array.prototype.push);
      var _shift = Function.call.bind(Array.prototype.shift);
      var _max = Math.max;
      var _min = Math.min;
      var _floor = Math.floor;
      var _abs = Math.abs;
      var _exp = Math.exp;
      var _log = Math.log;
      var _sqrt = Math.sqrt;
      var _hasOwnProperty = Function.call.bind(Object.prototype.hasOwnProperty);
      var ArrayIterator; // make our implementation private
      var noop = function () {};
  
      var OrigMap = globals.Map;
      var origMapDelete = OrigMap && OrigMap.prototype['delete'];
      var origMapGet = OrigMap && OrigMap.prototype.get;
      var origMapHas = OrigMap && OrigMap.prototype.has;
      var origMapSet = OrigMap && OrigMap.prototype.set;
  
      var Symbol = globals.Symbol || {};
      var symbolSpecies = Symbol.species || '@@species';
  
      var numberIsNaN = Number.isNaN || function isNaN(value) {
              // NaN !== NaN, but they are identical.
              // NaNs are the only non-reflexive value, i.e., if x !== x,
              // then x is NaN.
              // isNaN is broken: it converts its argument to number, so
              // isNaN('foo') => true
              return value !== value;
          };
      var numberIsFinite = Number.isFinite || function isFinite(value) {
              return typeof value === 'number' && globalIsFinite(value);
          };
      var _sign = isCallable(Math.sign) ? Math.sign : function sign(value) {
          var number = Number(value);
          if (number === 0) { return number; }
          if (numberIsNaN(number)) { return number; }
          return number < 0 ? -1 : 1;
      };
      var _log1p = function log1p(value) {
          var x = Number(value);
          if (x < -1 || numberIsNaN(x)) { return NaN; }
          if (x === 0 || x === Infinity) { return x; }
          if (x === -1) { return -Infinity; }
  
          return (1 + x) - 1 === 0 ? x : x * (_log(1 + x) / ((1 + x) - 1));
      };
  
      // taken directly from https://github.com/ljharb/is-arguments/blob/master/index.js
      // can be replaced with require('is-arguments') if we ever use a build process instead
      var isStandardArguments = function isArguments(value) {
          return _toString(value) === '[object Arguments]';
      };
      var isLegacyArguments = function isArguments(value) {
          return value !== null &&
              typeof value === 'object' &&
              typeof value.length === 'number' &&
              value.length >= 0 &&
              _toString(value) !== '[object Array]' &&
              _toString(value.callee) === '[object Function]';
      };
      var isArguments = isStandardArguments(arguments) ? isStandardArguments : isLegacyArguments;
  
      var Type = {
          primitive: function (x) { return x === null || (typeof x !== 'function' && typeof x !== 'object'); },
          string: function (x) { return _toString(x) === '[object String]'; },
          regex: function (x) { return _toString(x) === '[object RegExp]'; },
          symbol: function (x) {
              return typeof globals.Symbol === 'function' && typeof x === 'symbol';
          }
      };
  
      var overrideNative = function overrideNative(object, property, replacement) {
          var original = object[property];
          defineProperty(object, property, replacement, true);
          Value.preserveToString(object[property], original);
      };
  
      // eslint-disable-next-line no-restricted-properties
      var hasSymbols = typeof Symbol === 'function' && typeof Symbol['for'] === 'function' && Type.symbol(Symbol());
  
      // This is a private name in the es6 spec, equal to '[Symbol.iterator]'
      // we're going to use an arbitrary _-prefixed name to make our shims
      // work properly with each other, even though we don't have full Iterator
      // support.  That is, `Array.from(map.keys())` will work, but we don't
      // pretend to export a "real" Iterator interface.
      var $iterator$ = Type.symbol(Symbol.iterator) ? Symbol.iterator : '_es6-shim iterator_';
      // Firefox ships a partial implementation using the name @@iterator.
      // https://bugzilla.mozilla.org/show_bug.cgi?id=907077#c14
      // So use that name if we detect it.
      if (globals.Set && typeof new globals.Set()['@@iterator'] === 'function') {
          $iterator$ = '@@iterator';
      }
  
      // Reflect
      if (!globals.Reflect) {
          defineProperty(globals, 'Reflect', {}, true);
      }
      var Reflect = globals.Reflect;
  
      var $String = String;
  
      /* global document */
      var domAll = (typeof document === 'undefined' || !document) ? null : document.all;
      /* jshint eqnull:true */
      var isNullOrUndefined = domAll == null ? function isNullOrUndefined(x) {
          /* jshint eqnull:true */
          return x == null;
      } : function isNullOrUndefinedAndNotDocumentAll(x) {
          /* jshint eqnull:true */
          return x == null && x !== domAll;
      };
  
      var ES = {
          // http://www.ecma-international.org/ecma-262/6.0/#sec-call
          Call: function Call(F, V) {
              var args = arguments.length > 2 ? arguments[2] : [];
              if (!ES.IsCallable(F)) {
                  throw new TypeError(F + ' is not a function');
              }
              return _apply(F, V, args);
          },
  
          RequireObjectCoercible: function (x, optMessage) {
              if (isNullOrUndefined(x)) {
                  throw new TypeError(optMessage || 'Cannot call method on ' + x);
              }
              return x;
          },
  
          // This might miss the "(non-standard exotic and does not implement
          // [[Call]])" case from
          // http://www.ecma-international.org/ecma-262/6.0/#sec-typeof-operator-runtime-semantics-evaluation
          // but we can't find any evidence these objects exist in practice.
          // If we find some in the future, you could test `Object(x) === x`,
          // which is reliable according to
          // http://www.ecma-international.org/ecma-262/6.0/#sec-toobject
          // but is not well optimized by runtimes and creates an object
          // whenever it returns false, and thus is very slow.
          TypeIsObject: function (x) {
              if (x === void 0 || x === null || x === true || x === false) {
                  return false;
              }
              return typeof x === 'function' || typeof x === 'object' || x === domAll;
          },
  
          ToObject: function (o, optMessage) {
              return Object(ES.RequireObjectCoercible(o, optMessage));
          },
  
          IsCallable: isCallable,
  
          IsConstructor: function (x) {
              // We can't tell callables from constructors in ES5
              return ES.IsCallable(x);
          },
  
          ToInt32: function (x) {
              return ES.ToNumber(x) >> 0;
          },
  
          ToUint32: function (x) {
              return ES.ToNumber(x) >>> 0;
          },
  
          ToNumber: function (value) {
              if (_toString(value) === '[object Symbol]') {
                  throw new TypeError('Cannot convert a Symbol value to a number');
              }
              return +value;
          },
  
          ToInteger: function (value) {
              var number = ES.ToNumber(value);
              if (numberIsNaN(number)) { return 0; }
              if (number === 0 || !numberIsFinite(number)) { return number; }
              return (number > 0 ? 1 : -1) * _floor(_abs(number));
          },
  
          ToLength: function (value) {
              var len = ES.ToInteger(value);
              if (len <= 0) { return 0; } // includes converting -0 to +0
              if (len > Number.MAX_SAFE_INTEGER) { return Number.MAX_SAFE_INTEGER; }
              return len;
          },
  
          SameValue: function (a, b) {
              if (a === b) {
                  // 0 === -0, but they are not identical.
                  if (a === 0) { return 1 / a === 1 / b; }
                  return true;
              }
              return numberIsNaN(a) && numberIsNaN(b);
          },
  
          SameValueZero: function (a, b) {
              // same as SameValue except for SameValueZero(+0, -0) == true
              return (a === b) || (numberIsNaN(a) && numberIsNaN(b));
          },
  
          IsIterable: function (o) {
              return ES.TypeIsObject(o) && (typeof o[$iterator$] !== 'undefined' || isArguments(o));
          },
  
          GetIterator: function (o) {
              if (isArguments(o)) {
                  // special case support for `arguments`
                  return new ArrayIterator(o, 'value');
              }
              var itFn = ES.GetMethod(o, $iterator$);
              if (!ES.IsCallable(itFn)) {
                  // Better diagnostics if itFn is null or undefined
                  throw new TypeError('value is not an iterable');
              }
              var it = ES.Call(itFn, o);
              if (!ES.TypeIsObject(it)) {
                  throw new TypeError('bad iterator');
              }
              return it;
          },
  
          GetMethod: function (o, p) {
              var func = ES.ToObject(o)[p];
              if (isNullOrUndefined(func)) {
                  return void 0;
              }
              if (!ES.IsCallable(func)) {
                  throw new TypeError('Method not callable: ' + p);
              }
              return func;
          },
  
          IteratorComplete: function (iterResult) {
              return !!iterResult.done;
          },
  
          IteratorClose: function (iterator, completionIsThrow) {
              var returnMethod = ES.GetMethod(iterator, 'return');
              if (returnMethod === void 0) {
                  return;
              }
              var innerResult, innerException;
              try {
                  innerResult = ES.Call(returnMethod, iterator);
              } catch (e) {
                  innerException = e;
              }
              if (completionIsThrow) {
                  return;
              }
              if (innerException) {
                  throw innerException;
              }
              if (!ES.TypeIsObject(innerResult)) {
                  throw new TypeError("Iterator's return method returned a non-object.");
              }
          },
  
          IteratorNext: function (it) {
              var result = arguments.length > 1 ? it.next(arguments[1]) : it.next();
              if (!ES.TypeIsObject(result)) {
                  throw new TypeError('bad iterator');
              }
              return result;
          },
  
          IteratorStep: function (it) {
              var result = ES.IteratorNext(it);
              var done = ES.IteratorComplete(result);
              return done ? false : result;
          },
  
          Construct: function (C, args, newTarget, isES6internal) {
              var target = typeof newTarget === 'undefined' ? C : newTarget;
  
              if (!isES6internal && Reflect.construct) {
                  // Try to use Reflect.construct if available
                  return Reflect.construct(C, args, target);
              }
              // OK, we have to fake it.  This will only work if the
              // C.[[ConstructorKind]] == "base" -- but that's the only
              // kind we can make in ES5 code anyway.
  
              // OrdinaryCreateFromConstructor(target, "%ObjectPrototype%")
              var proto = target.prototype;
              if (!ES.TypeIsObject(proto)) {
                  proto = Object.prototype;
              }
              var obj = create(proto);
              // Call the constructor.
              var result = ES.Call(C, obj, args);
              return ES.TypeIsObject(result) ? result : obj;
          },
  
          SpeciesConstructor: function (O, defaultConstructor) {
              var C = O.constructor;
              if (C === void 0) {
                  return defaultConstructor;
              }
              if (!ES.TypeIsObject(C)) {
                  throw new TypeError('Bad constructor');
              }
              var S = C[symbolSpecies];
              if (isNullOrUndefined(S)) {
                  return defaultConstructor;
              }
              if (!ES.IsConstructor(S)) {
                  throw new TypeError('Bad @@species');
              }
              return S;
          },
  
          CreateHTML: function (string, tag, attribute, value) {
              var S = ES.ToString(string);
              var p1 = '<' + tag;
              if (attribute !== '') {
                  var V = ES.ToString(value);
                  var escapedV = V.replace(/"/g, '&quot;');
                  p1 += ' ' + attribute + '="' + escapedV + '"';
              }
              var p2 = p1 + '>';
              var p3 = p2 + S;
              return p3 + '</' + tag + '>';
          },
  
          IsRegExp: function IsRegExp(argument) {
              if (!ES.TypeIsObject(argument)) {
                  return false;
              }
              var isRegExp = argument[Symbol.match];
              if (typeof isRegExp !== 'undefined') {
                  return !!isRegExp;
              }
              return Type.regex(argument);
          },
  
          ToString: function ToString(string) {
              return $String(string);
          }
      };
  
      // Well-known Symbol shims
      if (supportsDescriptors && hasSymbols) {
          var defineWellKnownSymbol = function defineWellKnownSymbol(name) {
              if (Type.symbol(Symbol[name])) {
                  return Symbol[name];
              }
              // eslint-disable-next-line no-restricted-properties
              var sym = Symbol['for']('Symbol.' + name);
              Object.defineProperty(Symbol, name, {
                  configurable: false,
                  enumerable: false,
                  writable: false,
                  value: sym
              });
              return sym;
          };
          if (!Type.symbol(Symbol.search)) {
              var symbolSearch = defineWellKnownSymbol('search');
              var originalSearch = String.prototype.search;
              defineProperty(RegExp.prototype, symbolSearch, function search(string) {
                  return ES.Call(originalSearch, string, [this]);
              });
              var searchShim = function search(regexp) {
                  var O = ES.RequireObjectCoercible(this);
                  if (!isNullOrUndefined(regexp)) {
                      var searcher = ES.GetMethod(regexp, symbolSearch);
                      if (typeof searcher !== 'undefined') {
                          return ES.Call(searcher, regexp, [O]);
                      }
                  }
                  return ES.Call(originalSearch, O, [ES.ToString(regexp)]);
              };
              overrideNative(String.prototype, 'search', searchShim);
          }
          if (!Type.symbol(Symbol.replace)) {
              var symbolReplace = defineWellKnownSymbol('replace');
              var originalReplace = String.prototype.replace;
              defineProperty(RegExp.prototype, symbolReplace, function replace(string, replaceValue) {
                  return ES.Call(originalReplace, string, [this, replaceValue]);
              });
              var replaceShim = function replace(searchValue, replaceValue) {
                  var O = ES.RequireObjectCoercible(this);
                  if (!isNullOrUndefined(searchValue)) {
                      var replacer = ES.GetMethod(searchValue, symbolReplace);
                      if (typeof replacer !== 'undefined') {
                          return ES.Call(replacer, searchValue, [O, replaceValue]);
                      }
                  }
                  return ES.Call(originalReplace, O, [ES.ToString(searchValue), replaceValue]);
              };
              overrideNative(String.prototype, 'replace', replaceShim);
          }
          if (!Type.symbol(Symbol.split)) {
              var symbolSplit = defineWellKnownSymbol('split');
              var originalSplit = String.prototype.split;
              defineProperty(RegExp.prototype, symbolSplit, function split(string, limit) {
                  return ES.Call(originalSplit, string, [this, limit]);
              });
              var splitShim = function split(separator, limit) {
                  var O = ES.RequireObjectCoercible(this);
                  if (!isNullOrUndefined(separator)) {
                      var splitter = ES.GetMethod(separator, symbolSplit);
                      if (typeof splitter !== 'undefined') {
                          return ES.Call(splitter, separator, [O, limit]);
                      }
                  }
                  return ES.Call(originalSplit, O, [ES.ToString(separator), limit]);
              };
              overrideNative(String.prototype, 'split', splitShim);
          }
          var symbolMatchExists = Type.symbol(Symbol.match);
          var stringMatchIgnoresSymbolMatch = symbolMatchExists && (function () {
                  // Firefox 41, through Nightly 45 has Symbol.match, but String#match ignores it.
                  // Firefox 40 and below have Symbol.match but String#match works fine.
                  var o = {};
                  o[Symbol.match] = function () { return 42; };
                  return 'a'.match(o) !== 42;
              }());
          if (!symbolMatchExists || stringMatchIgnoresSymbolMatch) {
              var symbolMatch = defineWellKnownSymbol('match');
  
              var originalMatch = String.prototype.match;
              defineProperty(RegExp.prototype, symbolMatch, function match(string) {
                  return ES.Call(originalMatch, string, [this]);
              });
  
              var matchShim = function match(regexp) {
                  var O = ES.RequireObjectCoercible(this);
                  if (!isNullOrUndefined(regexp)) {
                      var matcher = ES.GetMethod(regexp, symbolMatch);
                      if (typeof matcher !== 'undefined') {
                          return ES.Call(matcher, regexp, [O]);
                      }
                  }
                  return ES.Call(originalMatch, O, [ES.ToString(regexp)]);
              };
              overrideNative(String.prototype, 'match', matchShim);
          }
      }
  
      var wrapConstructor = function wrapConstructor(original, replacement, keysToSkip) {
          Value.preserveToString(replacement, original);
          if (Object.setPrototypeOf) {
              // sets up proper prototype chain where possible
              Object.setPrototypeOf(original, replacement);
          }
          if (supportsDescriptors) {
              _forEach(Object.getOwnPropertyNames(original), function (key) {
                  if (key in noop || keysToSkip[key]) { return; }
                  Value.proxy(original, key, replacement);
              });
          } else {
              _forEach(Object.keys(original), function (key) {
                  if (key in noop || keysToSkip[key]) { return; }
                  replacement[key] = original[key];
              });
          }
          replacement.prototype = original.prototype;
          Value.redefine(original.prototype, 'constructor', replacement);
      };
  
      var defaultSpeciesGetter = function () { return this; };
      var addDefaultSpecies = function (C) {
          if (supportsDescriptors && !_hasOwnProperty(C, symbolSpecies)) {
              Value.getter(C, symbolSpecies, defaultSpeciesGetter);
          }
      };
  
      var addIterator = function (prototype, impl) {
          var implementation = impl || function iterator() { return this; };
          defineProperty(prototype, $iterator$, implementation);
          if (!prototype[$iterator$] && Type.symbol($iterator$)) {
              // implementations are buggy when $iterator$ is a Symbol
              prototype[$iterator$] = implementation;
          }
      };
  
      var createDataProperty = function createDataProperty(object, name, value) {
          if (supportsDescriptors) {
              Object.defineProperty(object, name, {
                  configurable: true,
                  enumerable: true,
                  writable: true,
                  value: value
              });
          } else {
              object[name] = value;
          }
      };
      var createDataPropertyOrThrow = function createDataPropertyOrThrow(object, name, value) {
          createDataProperty(object, name, value);
          if (!ES.SameValue(object[name], value)) {
              throw new TypeError('property is nonconfigurable');
          }
      };
  
      var emulateES6construct = function (o, defaultNewTarget, defaultProto, slots) {
          // This is an es5 approximation to es6 construct semantics.  in es6,
          // 'new Foo' invokes Foo.[[Construct]] which (for almost all objects)
          // just sets the internal variable NewTarget (in es6 syntax `new.target`)
          // to Foo and then returns Foo().
  
          // Many ES6 object then have constructors of the form:
          // 1. If NewTarget is undefined, throw a TypeError exception
          // 2. Let xxx by OrdinaryCreateFromConstructor(NewTarget, yyy, zzz)
  
          // So we're going to emulate those first two steps.
          if (!ES.TypeIsObject(o)) {
              throw new TypeError('Constructor requires `new`: ' + defaultNewTarget.name);
          }
          var proto = defaultNewTarget.prototype;
          if (!ES.TypeIsObject(proto)) {
              proto = defaultProto;
          }
          var obj = create(proto);
          for (var name in slots) {
              if (_hasOwnProperty(slots, name)) {
                  var value = slots[name];
                  defineProperty(obj, name, value, true);
              }
          }
          return obj;
      };
  
      // Firefox 31 reports this function's length as 0
      // https://bugzilla.mozilla.org/show_bug.cgi?id=1062484
      if (String.fromCodePoint && String.fromCodePoint.length !== 1) {
          var originalFromCodePoint = String.fromCodePoint;
          overrideNative(String, 'fromCodePoint', function fromCodePoint(codePoints) {
              return ES.Call(originalFromCodePoint, this, arguments);
          });
      }
  
      var StringShims = {
          fromCodePoint: function fromCodePoint(codePoints) {
              var result = [];
              var next;
              for (var i = 0, length = arguments.length; i < length; i++) {
                  next = Number(arguments[i]);
                  if (!ES.SameValue(next, ES.ToInteger(next)) || next < 0 || next > 0x10FFFF) {
                      throw new RangeError('Invalid code point ' + next);
                  }
  
                  if (next < 0x10000) {
                      _push(result, String.fromCharCode(next));
                  } else {
                      next -= 0x10000;
                      _push(result, String.fromCharCode((next >> 10) + 0xD800));
                      _push(result, String.fromCharCode((next % 0x400) + 0xDC00));
                  }
              }
              return result.join('');
          },
  
          raw: function raw(callSite) {
              var cooked = ES.ToObject(callSite, 'bad callSite');
              var rawString = ES.ToObject(cooked.raw, 'bad raw value');
              var len = rawString.length;
              var literalsegments = ES.ToLength(len);
              if (literalsegments <= 0) {
                  return '';
              }
  
              var stringElements = [];
              var nextIndex = 0;
              var nextKey, next, nextSeg, nextSub;
              while (nextIndex < literalsegments) {
                  nextKey = ES.ToString(nextIndex);
                  nextSeg = ES.ToString(rawString[nextKey]);
                  _push(stringElements, nextSeg);
                  if (nextIndex + 1 >= literalsegments) {
                      break;
                  }
                  next = nextIndex + 1 < arguments.length ? arguments[nextIndex + 1] : '';
                  nextSub = ES.ToString(next);
                  _push(stringElements, nextSub);
                  nextIndex += 1;
              }
              return stringElements.join('');
          }
      };
      if (String.raw && String.raw({ raw: { 0: 'x', 1: 'y', length: 2 } }) !== 'xy') {
          // IE 11 TP has a broken String.raw implementation
          overrideNative(String, 'raw', StringShims.raw);
      }
      defineProperties(String, StringShims);
  
      // Fast repeat, uses the `Exponentiation by squaring` algorithm.
      // Perf: http://jsperf.com/string-repeat2/2
      var stringRepeat = function repeat(s, times) {
          if (times < 1) { return ''; }
          if (times % 2) { return repeat(s, times - 1) + s; }
          var half = repeat(s, times / 2);
          return half + half;
      };
      var stringMaxLength = Infinity;
  
      var StringPrototypeShims = {
          repeat: function repeat(times) {
              var thisStr = ES.ToString(ES.RequireObjectCoercible(this));
              var numTimes = ES.ToInteger(times);
              if (numTimes < 0 || numTimes >= stringMaxLength) {
                  throw new RangeError('repeat count must be less than infinity and not overflow maximum string size');
              }
              return stringRepeat(thisStr, numTimes);
          },
  
          startsWith: function startsWith(searchString) {
              var S = ES.ToString(ES.RequireObjectCoercible(this));
              if (ES.IsRegExp(searchString)) {
                  throw new TypeError('Cannot call method "startsWith" with a regex');
              }
              var searchStr = ES.ToString(searchString);
              var position;
              if (arguments.length > 1) {
                  position = arguments[1];
              }
              var start = _max(ES.ToInteger(position), 0);
              return _strSlice(S, start, start + searchStr.length) === searchStr;
          },
  
          endsWith: function endsWith(searchString) {
              var S = ES.ToString(ES.RequireObjectCoercible(this));
              if (ES.IsRegExp(searchString)) {
                  throw new TypeError('Cannot call method "endsWith" with a regex');
              }
              var searchStr = ES.ToString(searchString);
              var len = S.length;
              var endPosition;
              if (arguments.length > 1) {
                  endPosition = arguments[1];
              }
              var pos = typeof endPosition === 'undefined' ? len : ES.ToInteger(endPosition);
              var end = _min(_max(pos, 0), len);
              return _strSlice(S, end - searchStr.length, end) === searchStr;
          },
  
          includes: function includes(searchString) {
              if (ES.IsRegExp(searchString)) {
                  throw new TypeError('"includes" does not accept a RegExp');
              }
              var searchStr = ES.ToString(searchString);
              var position;
              if (arguments.length > 1) {
                  position = arguments[1];
              }
              // Somehow this trick makes method 100% compat with the spec.
              return _indexOf(this, searchStr, position) !== -1;
          },
  
          codePointAt: function codePointAt(pos) {
              var thisStr = ES.ToString(ES.RequireObjectCoercible(this));
              var position = ES.ToInteger(pos);
              var length = thisStr.length;
              if (position >= 0 && position < length) {
                  var first = thisStr.charCodeAt(position);
                  var isEnd = position + 1 === length;
                  if (first < 0xD800 || first > 0xDBFF || isEnd) { return first; }
                  var second = thisStr.charCodeAt(position + 1);
                  if (second < 0xDC00 || second > 0xDFFF) { return first; }
                  return ((first - 0xD800) * 1024) + (second - 0xDC00) + 0x10000;
              }
          }
      };
      if (String.prototype.includes && 'a'.includes('a', Infinity) !== false) {
          overrideNative(String.prototype, 'includes', StringPrototypeShims.includes);
      }
  
      if (String.prototype.startsWith && String.prototype.endsWith) {
          var startsWithRejectsRegex = throwsError(function () {
              /* throws if spec-compliant */
              '/a/'.startsWith(/a/);
          });
          var startsWithHandlesInfinity = valueOrFalseIfThrows(function () {
              return 'abc'.startsWith('a', Infinity) === false;
          });
          if (!startsWithRejectsRegex || !startsWithHandlesInfinity) {
              // Firefox (< 37?) and IE 11 TP have a noncompliant startsWith implementation
              overrideNative(String.prototype, 'startsWith', StringPrototypeShims.startsWith);
              overrideNative(String.prototype, 'endsWith', StringPrototypeShims.endsWith);
          }
      }
      if (hasSymbols) {
          var startsWithSupportsSymbolMatch = valueOrFalseIfThrows(function () {
              var re = /a/;
              re[Symbol.match] = false;
              return '/a/'.startsWith(re);
          });
          if (!startsWithSupportsSymbolMatch) {
              overrideNative(String.prototype, 'startsWith', StringPrototypeShims.startsWith);
          }
          var endsWithSupportsSymbolMatch = valueOrFalseIfThrows(function () {
              var re = /a/;
              re[Symbol.match] = false;
              return '/a/'.endsWith(re);
          });
          if (!endsWithSupportsSymbolMatch) {
              overrideNative(String.prototype, 'endsWith', StringPrototypeShims.endsWith);
          }
          var includesSupportsSymbolMatch = valueOrFalseIfThrows(function () {
              var re = /a/;
              re[Symbol.match] = false;
              return '/a/'.includes(re);
          });
          if (!includesSupportsSymbolMatch) {
              overrideNative(String.prototype, 'includes', StringPrototypeShims.includes);
          }
      }
  
      defineProperties(String.prototype, StringPrototypeShims);
  
      // whitespace from: http://es5.github.io/#x15.5.4.20
      // implementation from https://github.com/es-shims/es5-shim/blob/v3.4.0/es5-shim.js#L1304-L1324
      var ws = [
          '\x09\x0A\x0B\x0C\x0D\x20\xA0\u1680\u180E\u2000\u2001\u2002\u2003',
          '\u2004\u2005\u2006\u2007\u2008\u2009\u200A\u202F\u205F\u3000\u2028',
          '\u2029\uFEFF'
      ].join('');
      var trimRegexp = new RegExp('(^[' + ws + ']+)|([' + ws + ']+$)', 'g');
      var trimShim = function trim() {
          return ES.ToString(ES.RequireObjectCoercible(this)).replace(trimRegexp, '');
      };
      var nonWS = ['\u0085', '\u200b', '\ufffe'].join('');
      var nonWSregex = new RegExp('[' + nonWS + ']', 'g');
      var isBadHexRegex = /^[-+]0x[0-9a-f]+$/i;
      var hasStringTrimBug = nonWS.trim().length !== nonWS.length;
      defineProperty(String.prototype, 'trim', trimShim, hasStringTrimBug);
  
      // Given an argument x, it will return an IteratorResult object,
      // with value set to x and done to false.
      // Given no arguments, it will return an iterator completion object.
      var iteratorResult = function (x) {
          return { value: x, done: arguments.length === 0 };
      };
  
      // see http://www.ecma-international.org/ecma-262/6.0/#sec-string.prototype-@@iterator
      var StringIterator = function (s) {
          ES.RequireObjectCoercible(s);
          this._s = ES.ToString(s);
          this._i = 0;
      };
      StringIterator.prototype.next = function () {
          var s = this._s;
          var i = this._i;
          if (typeof s === 'undefined' || i >= s.length) {
              this._s = void 0;
              return iteratorResult();
          }
          var first = s.charCodeAt(i);
          var second, len;
          if (first < 0xD800 || first > 0xDBFF || (i + 1) === s.length) {
              len = 1;
          } else {
              second = s.charCodeAt(i + 1);
              len = (second < 0xDC00 || second > 0xDFFF) ? 1 : 2;
          }
          this._i = i + len;
          return iteratorResult(s.substr(i, len));
      };
      addIterator(StringIterator.prototype);
      addIterator(String.prototype, function () {
          return new StringIterator(this);
      });
  
      var ArrayShims = {
          from: function from(items) {
              var C = this;
              var mapFn;
              if (arguments.length > 1) {
                  mapFn = arguments[1];
              }
              var mapping, T;
              if (typeof mapFn === 'undefined') {
                  mapping = false;
              } else {
                  if (!ES.IsCallable(mapFn)) {
                      throw new TypeError('Array.from: when provided, the second argument must be a function');
                  }
                  if (arguments.length > 2) {
                      T = arguments[2];
                  }
                  mapping = true;
              }
  
              // Note that that Arrays will use ArrayIterator:
              // https://bugs.ecmascript.org/show_bug.cgi?id=2416
              var usingIterator = typeof (isArguments(items) || ES.GetMethod(items, $iterator$)) !== 'undefined';
  
              var length, result, i;
              if (usingIterator) {
                  result = ES.IsConstructor(C) ? Object(new C()) : [];
                  var iterator = ES.GetIterator(items);
                  var next, nextValue;
  
                  i = 0;
                  while (true) {
                      next = ES.IteratorStep(iterator);
                      if (next === false) {
                          break;
                      }
                      nextValue = next.value;
                      try {
                          if (mapping) {
                              nextValue = typeof T === 'undefined' ? mapFn(nextValue, i) : _call(mapFn, T, nextValue, i);
                          }
                          result[i] = nextValue;
                      } catch (e) {
                          ES.IteratorClose(iterator, true);
                          throw e;
                      }
                      i += 1;
                  }
                  length = i;
              } else {
                  var arrayLike = ES.ToObject(items);
                  length = ES.ToLength(arrayLike.length);
                  result = ES.IsConstructor(C) ? Object(new C(length)) : new Array(length);
                  var value;
                  for (i = 0; i < length; ++i) {
                      value = arrayLike[i];
                      if (mapping) {
                          value = typeof T === 'undefined' ? mapFn(value, i) : _call(mapFn, T, value, i);
                      }
                      createDataPropertyOrThrow(result, i, value);
                  }
              }
  
              result.length = length;
              return result;
          },
  
          of: function of() {
              var len = arguments.length;
              var C = this;
              var A = isArray(C) || !ES.IsCallable(C) ? new Array(len) : ES.Construct(C, [len]);
              for (var k = 0; k < len; ++k) {
                  createDataPropertyOrThrow(A, k, arguments[k]);
              }
              A.length = len;
              return A;
          }
      };
      defineProperties(Array, ArrayShims);
      addDefaultSpecies(Array);
  
      // Our ArrayIterator is private; see
      // https://github.com/paulmillr/es6-shim/issues/252
      ArrayIterator = function (array, kind) {
          this.i = 0;
          this.array = array;
          this.kind = kind;
      };
  
      defineProperties(ArrayIterator.prototype, {
          next: function () {
              var i = this.i;
              var array = this.array;
              if (!(this instanceof ArrayIterator)) {
                  throw new TypeError('Not an ArrayIterator');
              }
              if (typeof array !== 'undefined') {
                  var len = ES.ToLength(array.length);
                  for (; i < len; i++) {
                      var kind = this.kind;
                      var retval;
                      if (kind === 'key') {
                          retval = i;
                      } else if (kind === 'value') {
                          retval = array[i];
                      } else if (kind === 'entry') {
                          retval = [i, array[i]];
                      }
                      this.i = i + 1;
                      return iteratorResult(retval);
                  }
              }
              this.array = void 0;
              return iteratorResult();
          }
      });
      addIterator(ArrayIterator.prototype);
  
      /*
       var orderKeys = function orderKeys(a, b) {
       var aNumeric = String(ES.ToInteger(a)) === a;
       var bNumeric = String(ES.ToInteger(b)) === b;
       if (aNumeric && bNumeric) {
       return b - a;
       } else if (aNumeric && !bNumeric) {
       return -1;
       } else if (!aNumeric && bNumeric) {
       return 1;
       } else {
       return a.localeCompare(b);
       }
       };
  
       var getAllKeys = function getAllKeys(object) {
       var ownKeys = [];
       var keys = [];
  
       for (var key in object) {
       _push(_hasOwnProperty(object, key) ? ownKeys : keys, key);
       }
       _sort(ownKeys, orderKeys);
       _sort(keys, orderKeys);
  
       return _concat(ownKeys, keys);
       };
       */
  
      // note: this is positioned here because it depends on ArrayIterator
      var arrayOfSupportsSubclassing = Array.of === ArrayShims.of || (function () {
              // Detects a bug in Webkit nightly r181886
              var Foo = function Foo(len) { this.length = len; };
              Foo.prototype = [];
              var fooArr = Array.of.apply(Foo, [1, 2]);
              return fooArr instanceof Foo && fooArr.length === 2;
          }());
      if (!arrayOfSupportsSubclassing) {
          overrideNative(Array, 'of', ArrayShims.of);
      }
  
      var ArrayPrototypeShims = {
          copyWithin: function copyWithin(target, start) {
              var o = ES.ToObject(this);
              var len = ES.ToLength(o.length);
              var relativeTarget = ES.ToInteger(target);
              var relativeStart = ES.ToInteger(start);
              var to = relativeTarget < 0 ? _max(len + relativeTarget, 0) : _min(relativeTarget, len);
              var from = relativeStart < 0 ? _max(len + relativeStart, 0) : _min(relativeStart, len);
              var end;
              if (arguments.length > 2) {
                  end = arguments[2];
              }
              var relativeEnd = typeof end === 'undefined' ? len : ES.ToInteger(end);
              var finalItem = relativeEnd < 0 ? _max(len + relativeEnd, 0) : _min(relativeEnd, len);
              var count = _min(finalItem - from, len - to);
              var direction = 1;
              if (from < to && to < (from + count)) {
                  direction = -1;
                  from += count - 1;
                  to += count - 1;
              }
              while (count > 0) {
                  if (from in o) {
                      o[to] = o[from];
                  } else {
                      delete o[to];
                  }
                  from += direction;
                  to += direction;
                  count -= 1;
              }
              return o;
          },
  
          fill: function fill(value) {
              var start;
              if (arguments.length > 1) {
                  start = arguments[1];
              }
              var end;
              if (arguments.length > 2) {
                  end = arguments[2];
              }
              var O = ES.ToObject(this);
              var len = ES.ToLength(O.length);
              start = ES.ToInteger(typeof start === 'undefined' ? 0 : start);
              end = ES.ToInteger(typeof end === 'undefined' ? len : end);
  
              var relativeStart = start < 0 ? _max(len + start, 0) : _min(start, len);
              var relativeEnd = end < 0 ? len + end : end;
  
              for (var i = relativeStart; i < len && i < relativeEnd; ++i) {
                  O[i] = value;
              }
              return O;
          },
  
          find: function find(predicate) {
              var list = ES.ToObject(this);
              var length = ES.ToLength(list.length);
              if (!ES.IsCallable(predicate)) {
                  throw new TypeError('Array#find: predicate must be a function');
              }
              var thisArg = arguments.length > 1 ? arguments[1] : null;
              for (var i = 0, value; i < length; i++) {
                  value = list[i];
                  if (thisArg) {
                      if (_call(predicate, thisArg, value, i, list)) {
                          return value;
                      }
                  } else if (predicate(value, i, list)) {
                      return value;
                  }
              }
          },
  
          findIndex: function findIndex(predicate) {
              var list = ES.ToObject(this);
              var length = ES.ToLength(list.length);
              if (!ES.IsCallable(predicate)) {
                  throw new TypeError('Array#findIndex: predicate must be a function');
              }
              var thisArg = arguments.length > 1 ? arguments[1] : null;
              for (var i = 0; i < length; i++) {
                  if (thisArg) {
                      if (_call(predicate, thisArg, list[i], i, list)) {
                          return i;
                      }
                  } else if (predicate(list[i], i, list)) {
                      return i;
                  }
              }
              return -1;
          },
  
          keys: function keys() {
              return new ArrayIterator(this, 'key');
          },
  
          values: function values() {
              return new ArrayIterator(this, 'value');
          },
  
          entries: function entries() {
              return new ArrayIterator(this, 'entry');
          }
      };
      // Safari 7.1 defines Array#keys and Array#entries natively,
      // but the resulting ArrayIterator objects don't have a "next" method.
      if (Array.prototype.keys && !ES.IsCallable([1].keys().next)) {
          delete Array.prototype.keys;
      }
      if (Array.prototype.entries && !ES.IsCallable([1].entries().next)) {
          delete Array.prototype.entries;
      }
  
      // Chrome 38 defines Array#keys and Array#entries, and Array#@@iterator, but not Array#values
      if (Array.prototype.keys && Array.prototype.entries && !Array.prototype.values && Array.prototype[$iterator$]) {
          defineProperties(Array.prototype, {
              values: Array.prototype[$iterator$]
          });
          if (Type.symbol(Symbol.unscopables)) {
              Array.prototype[Symbol.unscopables].values = true;
          }
      }
      // Chrome 40 defines Array#values with the incorrect name, although Array#{keys,entries} have the correct name
      if (functionsHaveNames && Array.prototype.values && Array.prototype.values.name !== 'values') {
          var originalArrayPrototypeValues = Array.prototype.values;
          overrideNative(Array.prototype, 'values', function values() { return ES.Call(originalArrayPrototypeValues, this, arguments); });
          defineProperty(Array.prototype, $iterator$, Array.prototype.values, true);
      }
      defineProperties(Array.prototype, ArrayPrototypeShims);
  
      if (1 / [true].indexOf(true, -0) < 0) {
          // indexOf when given a position arg of -0 should return +0.
          // https://github.com/tc39/ecma262/pull/316
          defineProperty(Array.prototype, 'indexOf', function indexOf(searchElement) {
              var value = _arrayIndexOfApply(this, arguments);
              if (value === 0 && (1 / value) < 0) {
                  return 0;
              }
              return value;
          }, true);
      }
  
      addIterator(Array.prototype, function () { return this.values(); });
      // Chrome defines keys/values/entries on Array, but doesn't give us
      // any way to identify its iterator.  So add our own shimmed field.
      if (Object.getPrototypeOf) {
          addIterator(Object.getPrototypeOf([].values()));
      }
  
      // note: this is positioned here because it relies on Array#entries
      var arrayFromSwallowsNegativeLengths = (function () {
          // Detects a Firefox bug in v32
          // https://bugzilla.mozilla.org/show_bug.cgi?id=1063993
          return valueOrFalseIfThrows(function () {
              return Array.from({ length: -1 }).length === 0;
          });
      }());
      var arrayFromHandlesIterables = (function () {
          // Detects a bug in Webkit nightly r181886
          var arr = Array.from([0].entries());
          return arr.length === 1 && isArray(arr[0]) && arr[0][0] === 0 && arr[0][1] === 0;
      }());
      if (!arrayFromSwallowsNegativeLengths || !arrayFromHandlesIterables) {
          overrideNative(Array, 'from', ArrayShims.from);
      }
      var arrayFromHandlesUndefinedMapFunction = (function () {
          // Microsoft Edge v0.11 throws if the mapFn argument is *provided* but undefined,
          // but the spec doesn't care if it's provided or not - undefined doesn't throw.
          return valueOrFalseIfThrows(function () {
              return Array.from([0], void 0);
          });
      }());
      if (!arrayFromHandlesUndefinedMapFunction) {
          var origArrayFrom = Array.from;
          overrideNative(Array, 'from', function from(items) {
              if (arguments.length > 1 && typeof arguments[1] !== 'undefined') {
                  return ES.Call(origArrayFrom, this, arguments);
              } else {
                  return _call(origArrayFrom, this, items);
              }
          });
      }
  
      var int32sAsOne = -(Math.pow(2, 32) - 1);
      var toLengthsCorrectly = function (method, reversed) {
          var obj = { length: int32sAsOne };
          obj[reversed ? (obj.length >>> 0) - 1 : 0] = true;
          return valueOrFalseIfThrows(function () {
              _call(method, obj, function () {
                  // note: in nonconforming browsers, this will be called
                  // -1 >>> 0 times, which is 4294967295, so the throw matters.
                  throw new RangeError('should not reach here');
              }, []);
              return true;
          });
      };
      if (!toLengthsCorrectly(Array.prototype.forEach)) {
          var originalForEach = Array.prototype.forEach;
          overrideNative(Array.prototype, 'forEach', function forEach(callbackFn) {
              return ES.Call(originalForEach, this.length >= 0 ? this : [], arguments);
          }, true);
      }
      if (!toLengthsCorrectly(Array.prototype.map)) {
          var originalMap = Array.prototype.map;
          overrideNative(Array.prototype, 'map', function map(callbackFn) {
              return ES.Call(originalMap, this.length >= 0 ? this : [], arguments);
          }, true);
      }
      if (!toLengthsCorrectly(Array.prototype.filter)) {
          var originalFilter = Array.prototype.filter;
          overrideNative(Array.prototype, 'filter', function filter(callbackFn) {
              return ES.Call(originalFilter, this.length >= 0 ? this : [], arguments);
          }, true);
      }
      if (!toLengthsCorrectly(Array.prototype.some)) {
          var originalSome = Array.prototype.some;
          overrideNative(Array.prototype, 'some', function some(callbackFn) {
              return ES.Call(originalSome, this.length >= 0 ? this : [], arguments);
          }, true);
      }
      if (!toLengthsCorrectly(Array.prototype.every)) {
          var originalEvery = Array.prototype.every;
          overrideNative(Array.prototype, 'every', function every(callbackFn) {
              return ES.Call(originalEvery, this.length >= 0 ? this : [], arguments);
          }, true);
      }
      if (!toLengthsCorrectly(Array.prototype.reduce)) {
          var originalReduce = Array.prototype.reduce;
          overrideNative(Array.prototype, 'reduce', function reduce(callbackFn) {
              return ES.Call(originalReduce, this.length >= 0 ? this : [], arguments);
          }, true);
      }
      if (!toLengthsCorrectly(Array.prototype.reduceRight, true)) {
          var originalReduceRight = Array.prototype.reduceRight;
          overrideNative(Array.prototype, 'reduceRight', function reduceRight(callbackFn) {
              return ES.Call(originalReduceRight, this.length >= 0 ? this : [], arguments);
          }, true);
      }
  
      var lacksOctalSupport = Number('0o10') !== 8;
      var lacksBinarySupport = Number('0b10') !== 2;
      var trimsNonWhitespace = _some(nonWS, function (c) {
          return Number(c + 0 + c) === 0;
      });
      if (lacksOctalSupport || lacksBinarySupport || trimsNonWhitespace) {
          var OrigNumber = Number;
          var binaryRegex = /^0b[01]+$/i;
          var octalRegex = /^0o[0-7]+$/i;
          // Note that in IE 8, RegExp.prototype.test doesn't seem to exist: ie, "test" is an own property of regexes. wtf.
          var isBinary = binaryRegex.test.bind(binaryRegex);
          var isOctal = octalRegex.test.bind(octalRegex);
          var toPrimitive = function (O) { // need to replace this with `es-to-primitive/es6`
              var result;
              if (typeof O.valueOf === 'function') {
                  result = O.valueOf();
                  if (Type.primitive(result)) {
                      return result;
                  }
              }
              if (typeof O.toString === 'function') {
                  result = O.toString();
                  if (Type.primitive(result)) {
                      return result;
                  }
              }
              throw new TypeError('No default value');
          };
          var hasNonWS = nonWSregex.test.bind(nonWSregex);
          var isBadHex = isBadHexRegex.test.bind(isBadHexRegex);
          var NumberShim = (function () {
              // this is wrapped in an IIFE because of IE 6-8's wacky scoping issues with named function expressions.
              var NumberShim = function Number(value) {
                  var primValue;
                  if (arguments.length > 0) {
                      primValue = Type.primitive(value) ? value : toPrimitive(value, 'number');
                  } else {
                      primValue = 0;
                  }
                  if (typeof primValue === 'string') {
                      primValue = ES.Call(trimShim, primValue);
                      if (isBinary(primValue)) {
                          primValue = parseInt(_strSlice(primValue, 2), 2);
                      } else if (isOctal(primValue)) {
                          primValue = parseInt(_strSlice(primValue, 2), 8);
                      } else if (hasNonWS(primValue) || isBadHex(primValue)) {
                          primValue = NaN;
                      }
                  }
                  var receiver = this;
                  var valueOfSucceeds = valueOrFalseIfThrows(function () {
                      OrigNumber.prototype.valueOf.call(receiver);
                      return true;
                  });
                  if (receiver instanceof NumberShim && !valueOfSucceeds) {
                      return new OrigNumber(primValue);
                  }
                  /* jshint newcap: false */
                  return OrigNumber(primValue);
                  /* jshint newcap: true */
              };
              return NumberShim;
          }());
          wrapConstructor(OrigNumber, NumberShim, {});
          // this is necessary for ES3 browsers, where these properties are non-enumerable.
          defineProperties(NumberShim, {
              NaN: OrigNumber.NaN,
              MAX_VALUE: OrigNumber.MAX_VALUE,
              MIN_VALUE: OrigNumber.MIN_VALUE,
              NEGATIVE_INFINITY: OrigNumber.NEGATIVE_INFINITY,
              POSITIVE_INFINITY: OrigNumber.POSITIVE_INFINITY
          });
          /* globals Number: true */
          /* eslint-disable no-undef, no-global-assign */
          /* jshint -W020 */
          Number = NumberShim;
          Value.redefine(globals, 'Number', NumberShim);
          /* jshint +W020 */
          /* eslint-enable no-undef, no-global-assign */
          /* globals Number: false */
      }
  
      var maxSafeInteger = Math.pow(2, 53) - 1;
      defineProperties(Number, {
          MAX_SAFE_INTEGER: maxSafeInteger,
          MIN_SAFE_INTEGER: -maxSafeInteger,
          EPSILON: 2.220446049250313e-16,
  
          parseInt: globals.parseInt,
          parseFloat: globals.parseFloat,
  
          isFinite: numberIsFinite,
  
          isInteger: function isInteger(value) {
              return numberIsFinite(value) && ES.ToInteger(value) === value;
          },
  
          isSafeInteger: function isSafeInteger(value) {
              return Number.isInteger(value) && _abs(value) <= Number.MAX_SAFE_INTEGER;
          },
  
          isNaN: numberIsNaN
      });
      // Firefox 37 has a conforming Number.parseInt, but it's not === to the global parseInt (fixed in v40)
      defineProperty(Number, 'parseInt', globals.parseInt, Number.parseInt !== globals.parseInt);
  
      // Work around bugs in Array#find and Array#findIndex -- early
      // implementations skipped holes in sparse arrays. (Note that the
      // implementations of find/findIndex indirectly use shimmed
      // methods of Number, so this test has to happen down here.)
      /*jshint elision: true */
      /* eslint-disable no-sparse-arrays */
      if ([, 1].find(function () { return true; }) === 1) {
          overrideNative(Array.prototype, 'find', ArrayPrototypeShims.find);
      }
      if ([, 1].findIndex(function () { return true; }) !== 0) {
          overrideNative(Array.prototype, 'findIndex', ArrayPrototypeShims.findIndex);
      }
      /* eslint-enable no-sparse-arrays */
      /*jshint elision: false */
  
      var isEnumerableOn = Function.bind.call(Function.bind, Object.prototype.propertyIsEnumerable);
      var ensureEnumerable = function ensureEnumerable(obj, prop) {
          if (supportsDescriptors && isEnumerableOn(obj, prop)) {
              Object.defineProperty(obj, prop, { enumerable: false });
          }
      };
      var sliceArgs = function sliceArgs() {
          // per https://github.com/petkaantonov/bluebird/wiki/Optimization-killers#32-leaking-arguments
          // and https://gist.github.com/WebReflection/4327762cb87a8c634a29
          var initial = Number(this);
          var len = arguments.length;
          var desiredArgCount = len - initial;
          var args = new Array(desiredArgCount < 0 ? 0 : desiredArgCount);
          for (var i = initial; i < len; ++i) {
              args[i - initial] = arguments[i];
          }
          return args;
      };
      var assignTo = function assignTo(source) {
          return function assignToSource(target, key) {
              target[key] = source[key];
              return target;
          };
      };
      var assignReducer = function (target, source) {
          var sourceKeys = keys(Object(source));
          var symbols;
          if (ES.IsCallable(Object.getOwnPropertySymbols)) {
              symbols = _filter(Object.getOwnPropertySymbols(Object(source)), isEnumerableOn(source));
          }
          return _reduce(_concat(sourceKeys, symbols || []), assignTo(source), target);
      };
  
      var ObjectShims = {
          // 19.1.3.1
          assign: function (target, source) {
              var to = ES.ToObject(target, 'Cannot convert undefined or null to object');
              return _reduce(ES.Call(sliceArgs, 1, arguments), assignReducer, to);
          },
  
          // Added in WebKit in https://bugs.webkit.org/show_bug.cgi?id=143865
          is: function is(a, b) {
              return ES.SameValue(a, b);
          }
      };
      var assignHasPendingExceptions = Object.assign && Object.preventExtensions && (function () {
              // Firefox 37 still has "pending exception" logic in its Object.assign implementation,
              // which is 72% slower than our shim, and Firefox 40's native implementation.
              var thrower = Object.preventExtensions({ 1: 2 });
              try {
                  Object.assign(thrower, 'xy');
              } catch (e) {
                  return thrower[1] === 'y';
              }
          }());
      if (assignHasPendingExceptions) {
          overrideNative(Object, 'assign', ObjectShims.assign);
      }
      defineProperties(Object, ObjectShims);
  
      if (supportsDescriptors) {
          var ES5ObjectShims = {
              // 19.1.3.9
              // shim from https://gist.github.com/WebReflection/5593554
              setPrototypeOf: (function (Object, magic) {
                  var set;
  
                  var checkArgs = function (O, proto) {
                      if (!ES.TypeIsObject(O)) {
                          throw new TypeError('cannot set prototype on a non-object');
                      }
                      if (!(proto === null || ES.TypeIsObject(proto))) {
                          throw new TypeError('can only set prototype to an object or null' + proto);
                      }
                  };
  
                  var setPrototypeOf = function (O, proto) {
                      checkArgs(O, proto);
                      _call(set, O, proto);
                      return O;
                  };
  
                  try {
                      // this works already in Firefox and Safari
                      set = Object.getOwnPropertyDescriptor(Object.prototype, magic).set;
                      _call(set, {}, null);
                  } catch (e) {
                      if (Object.prototype !== {}[magic]) {
                          // IE < 11 cannot be shimmed
                          return;
                      }
                      // probably Chrome or some old Mobile stock browser
                      set = function (proto) {
                          this[magic] = proto;
                      };
                      // please note that this will **not** work
                      // in those browsers that do not inherit
                      // __proto__ by mistake from Object.prototype
                      // in these cases we should probably throw an error
                      // or at least be informed about the issue
                      setPrototypeOf.polyfill = setPrototypeOf(
                              setPrototypeOf({}, null),
                              Object.prototype
                          ) instanceof Object;
                      // setPrototypeOf.polyfill === true means it works as meant
                      // setPrototypeOf.polyfill === false means it's not 100% reliable
                      // setPrototypeOf.polyfill === undefined
                      // or
                      // setPrototypeOf.polyfill ==  null means it's not a polyfill
                      // which means it works as expected
                      // we can even delete Object.prototype.__proto__;
                  }
                  return setPrototypeOf;
              }(Object, '__proto__'))
          };
  
          defineProperties(Object, ES5ObjectShims);
      }
  
      // Workaround bug in Opera 12 where setPrototypeOf(x, null) doesn't work,
      // but Object.create(null) does.
      if (Object.setPrototypeOf && Object.getPrototypeOf &&
          Object.getPrototypeOf(Object.setPrototypeOf({}, null)) !== null &&
          Object.getPrototypeOf(Object.create(null)) === null) {
          (function () {
              var FAKENULL = Object.create(null);
              var gpo = Object.getPrototypeOf;
              var spo = Object.setPrototypeOf;
              Object.getPrototypeOf = function (o) {
                  var result = gpo(o);
                  return result === FAKENULL ? null : result;
              };
              Object.setPrototypeOf = function (o, p) {
                  var proto = p === null ? FAKENULL : p;
                  return spo(o, proto);
              };
              Object.setPrototypeOf.polyfill = false;
          }());
      }
  
      var objectKeysAcceptsPrimitives = !throwsError(function () { Object.keys('foo'); });
      if (!objectKeysAcceptsPrimitives) {
          var originalObjectKeys = Object.keys;
          overrideNative(Object, 'keys', function keys(value) {
              return originalObjectKeys(ES.ToObject(value));
          });
          keys = Object.keys;
      }
      var objectKeysRejectsRegex = throwsError(function () { Object.keys(/a/g); });
      if (objectKeysRejectsRegex) {
          var regexRejectingObjectKeys = Object.keys;
          overrideNative(Object, 'keys', function keys(value) {
              if (Type.regex(value)) {
                  var regexKeys = [];
                  for (var k in value) {
                      if (_hasOwnProperty(value, k)) {
                          _push(regexKeys, k);
                      }
                  }
                  return regexKeys;
              }
              return regexRejectingObjectKeys(value);
          });
          keys = Object.keys;
      }
  
      if (Object.getOwnPropertyNames) {
          var objectGOPNAcceptsPrimitives = !throwsError(function () { Object.getOwnPropertyNames('foo'); });
          if (!objectGOPNAcceptsPrimitives) {
              var cachedWindowNames = typeof window === 'object' ? Object.getOwnPropertyNames(window) : [];
              var originalObjectGetOwnPropertyNames = Object.getOwnPropertyNames;
              overrideNative(Object, 'getOwnPropertyNames', function getOwnPropertyNames(value) {
                  var val = ES.ToObject(value);
                  if (_toString(val) === '[object Window]') {
                      try {
                          return originalObjectGetOwnPropertyNames(val);
                      } catch (e) {
                          // IE bug where layout engine calls userland gOPN for cross-domain `window` objects
                          return _concat([], cachedWindowNames);
                      }
                  }
                  return originalObjectGetOwnPropertyNames(val);
              });
          }
      }
      if (Object.getOwnPropertyDescriptor) {
          var objectGOPDAcceptsPrimitives = !throwsError(function () { Object.getOwnPropertyDescriptor('foo', 'bar'); });
          if (!objectGOPDAcceptsPrimitives) {
              var originalObjectGetOwnPropertyDescriptor = Object.getOwnPropertyDescriptor;
              overrideNative(Object, 'getOwnPropertyDescriptor', function getOwnPropertyDescriptor(value, property) {
                  return originalObjectGetOwnPropertyDescriptor(ES.ToObject(value), property);
              });
          }
      }
      if (Object.seal) {
          var objectSealAcceptsPrimitives = !throwsError(function () { Object.seal('foo'); });
          if (!objectSealAcceptsPrimitives) {
              var originalObjectSeal = Object.seal;
              overrideNative(Object, 'seal', function seal(value) {
                  if (!ES.TypeIsObject(value)) { return value; }
                  return originalObjectSeal(value);
              });
          }
      }
      if (Object.isSealed) {
          var objectIsSealedAcceptsPrimitives = !throwsError(function () { Object.isSealed('foo'); });
          if (!objectIsSealedAcceptsPrimitives) {
              var originalObjectIsSealed = Object.isSealed;
              overrideNative(Object, 'isSealed', function isSealed(value) {
                  if (!ES.TypeIsObject(value)) { return true; }
                  return originalObjectIsSealed(value);
              });
          }
      }
      if (Object.freeze) {
          var objectFreezeAcceptsPrimitives = !throwsError(function () { Object.freeze('foo'); });
          if (!objectFreezeAcceptsPrimitives) {
              var originalObjectFreeze = Object.freeze;
              overrideNative(Object, 'freeze', function freeze(value) {
                  if (!ES.TypeIsObject(value)) { return value; }
                  return originalObjectFreeze(value);
              });
          }
      }
      if (Object.isFrozen) {
          var objectIsFrozenAcceptsPrimitives = !throwsError(function () { Object.isFrozen('foo'); });
          if (!objectIsFrozenAcceptsPrimitives) {
              var originalObjectIsFrozen = Object.isFrozen;
              overrideNative(Object, 'isFrozen', function isFrozen(value) {
                  if (!ES.TypeIsObject(value)) { return true; }
                  return originalObjectIsFrozen(value);
              });
          }
      }
      if (Object.preventExtensions) {
          var objectPreventExtensionsAcceptsPrimitives = !throwsError(function () { Object.preventExtensions('foo'); });
          if (!objectPreventExtensionsAcceptsPrimitives) {
              var originalObjectPreventExtensions = Object.preventExtensions;
              overrideNative(Object, 'preventExtensions', function preventExtensions(value) {
                  if (!ES.TypeIsObject(value)) { return value; }
                  return originalObjectPreventExtensions(value);
              });
          }
      }
      if (Object.isExtensible) {
          var objectIsExtensibleAcceptsPrimitives = !throwsError(function () { Object.isExtensible('foo'); });
          if (!objectIsExtensibleAcceptsPrimitives) {
              var originalObjectIsExtensible = Object.isExtensible;
              overrideNative(Object, 'isExtensible', function isExtensible(value) {
                  if (!ES.TypeIsObject(value)) { return false; }
                  return originalObjectIsExtensible(value);
              });
          }
      }
      if (Object.getPrototypeOf) {
          var objectGetProtoAcceptsPrimitives = !throwsError(function () { Object.getPrototypeOf('foo'); });
          if (!objectGetProtoAcceptsPrimitives) {
              var originalGetProto = Object.getPrototypeOf;
              overrideNative(Object, 'getPrototypeOf', function getPrototypeOf(value) {
                  return originalGetProto(ES.ToObject(value));
              });
          }
      }
  
      var hasFlags = supportsDescriptors && (function () {
              var desc = Object.getOwnPropertyDescriptor(RegExp.prototype, 'flags');
              return desc && ES.IsCallable(desc.get);
          }());
      if (supportsDescriptors && !hasFlags) {
          var regExpFlagsGetter = function flags() {
              if (!ES.TypeIsObject(this)) {
                  throw new TypeError('Method called on incompatible type: must be an object.');
              }
              var result = '';
              if (this.global) {
                  result += 'g';
              }
              if (this.ignoreCase) {
                  result += 'i';
              }
              if (this.multiline) {
                  result += 'm';
              }
              if (this.unicode) {
                  result += 'u';
              }
              if (this.sticky) {
                  result += 'y';
              }
              return result;
          };
  
          Value.getter(RegExp.prototype, 'flags', regExpFlagsGetter);
      }
  
      var regExpSupportsFlagsWithRegex = supportsDescriptors && valueOrFalseIfThrows(function () {
              return String(new RegExp(/a/g, 'i')) === '/a/i';
          });
      var regExpNeedsToSupportSymbolMatch = hasSymbols && supportsDescriptors && (function () {
              // Edge 0.12 supports flags fully, but does not support Symbol.match
              var regex = /./;
              regex[Symbol.match] = false;
              return RegExp(regex) === regex;
          }());
  
      var regexToStringIsGeneric = valueOrFalseIfThrows(function () {
          return RegExp.prototype.toString.call({ source: 'abc' }) === '/abc/';
      });
      var regexToStringSupportsGenericFlags = regexToStringIsGeneric && valueOrFalseIfThrows(function () {
              return RegExp.prototype.toString.call({ source: 'a', flags: 'b' }) === '/a/b';
          });
      if (!regexToStringIsGeneric || !regexToStringSupportsGenericFlags) {
          var origRegExpToString = RegExp.prototype.toString;
          defineProperty(RegExp.prototype, 'toString', function toString() {
              var R = ES.RequireObjectCoercible(this);
              if (Type.regex(R)) {
                  return _call(origRegExpToString, R);
              }
              var pattern = $String(R.source);
              var flags = $String(R.flags);
              return '/' + pattern + '/' + flags;
          }, true);
          Value.preserveToString(RegExp.prototype.toString, origRegExpToString);
      }
  
      if (supportsDescriptors && (!regExpSupportsFlagsWithRegex || regExpNeedsToSupportSymbolMatch)) {
          var flagsGetter = Object.getOwnPropertyDescriptor(RegExp.prototype, 'flags').get;
          var sourceDesc = Object.getOwnPropertyDescriptor(RegExp.prototype, 'source') || {};
          var legacySourceGetter = function () {
              // prior to it being a getter, it's own + nonconfigurable
              return this.source;
          };
          var sourceGetter = ES.IsCallable(sourceDesc.get) ? sourceDesc.get : legacySourceGetter;
  
          var OrigRegExp = RegExp;
          var RegExpShim = (function () {
              return function RegExp(pattern, flags) {
                  var patternIsRegExp = ES.IsRegExp(pattern);
                  var calledWithNew = this instanceof RegExp;
                  if (!calledWithNew && patternIsRegExp && typeof flags === 'undefined' && pattern.constructor === RegExp) {
                      return pattern;
                  }
  
                  var P = pattern;
                  var F = flags;
                  if (Type.regex(pattern)) {
                      P = ES.Call(sourceGetter, pattern);
                      F = typeof flags === 'undefined' ? ES.Call(flagsGetter, pattern) : flags;
                      return new RegExp(P, F);
                  } else if (patternIsRegExp) {
                      P = pattern.source;
                      F = typeof flags === 'undefined' ? pattern.flags : flags;
                  }
                  return new OrigRegExp(pattern, flags);
              };
          }());
          wrapConstructor(OrigRegExp, RegExpShim, {
              $input: true // Chrome < v39 & Opera < 26 have a nonstandard "$input" property
          });
          /* globals RegExp: true */
          /* eslint-disable no-undef, no-global-assign */
          /* jshint -W020 */
          RegExp = RegExpShim;
          Value.redefine(globals, 'RegExp', RegExpShim);
          /* jshint +W020 */
          /* eslint-enable no-undef, no-global-assign */
          /* globals RegExp: false */
      }
  
      if (supportsDescriptors) {
          var regexGlobals = {
              input: '$_',
              lastMatch: '$&',
              lastParen: '$+',
              leftContext: '$`',
              rightContext: '$\''
          };
          _forEach(keys(regexGlobals), function (prop) {
              if (prop in RegExp && !(regexGlobals[prop] in RegExp)) {
                  Value.getter(RegExp, regexGlobals[prop], function get() {
                      return RegExp[prop];
                  });
              }
          });
      }
      addDefaultSpecies(RegExp);
  
      var inverseEpsilon = 1 / Number.EPSILON;
      var roundTiesToEven = function roundTiesToEven(n) {
          // Even though this reduces down to `return n`, it takes advantage of built-in rounding.
          return (n + inverseEpsilon) - inverseEpsilon;
      };
      var BINARY_32_EPSILON = Math.pow(2, -23);
      var BINARY_32_MAX_VALUE = Math.pow(2, 127) * (2 - BINARY_32_EPSILON);
      var BINARY_32_MIN_VALUE = Math.pow(2, -126);
      var E = Math.E;
      var LOG2E = Math.LOG2E;
      var LOG10E = Math.LOG10E;
      var numberCLZ = Number.prototype.clz;
      delete Number.prototype.clz; // Safari 8 has Number#clz
  
      var MathShims = {
          acosh: function acosh(value) {
              var x = Number(value);
              if (numberIsNaN(x) || value < 1) { return NaN; }
              if (x === 1) { return 0; }
              if (x === Infinity) { return x; }
  
              var xInvSquared = 1 / (x * x);
              if (x < 2) {
                  return _log1p(x - 1 + (_sqrt(1 - xInvSquared) * x));
              }
              var halfX = x / 2;
              return _log1p(halfX + (_sqrt(1 - xInvSquared) * halfX) - 1) + (1 / LOG2E);
          },
  
          asinh: function asinh(value) {
              var x = Number(value);
              if (x === 0 || !globalIsFinite(x)) {
                  return x;
              }
  
              var a = _abs(x);
              var aSquared = a * a;
              var s = _sign(x);
              if (a < 1) {
                  return s * _log1p(a + (aSquared / (_sqrt(aSquared + 1) + 1)));
              }
              return s * (_log1p((a / 2) + (_sqrt(1 + (1 / aSquared)) * a / 2) - 1) + (1 / LOG2E));
          },
  
          atanh: function atanh(value) {
              var x = Number(value);
  
              if (x === 0) { return x; }
              if (x === -1) { return -Infinity; }
              if (x === 1) { return Infinity; }
              if (numberIsNaN(x) || x < -1 || x > 1) {
                  return NaN;
              }
  
              var a = _abs(x);
              return _sign(x) * _log1p(2 * a / (1 - a)) / 2;
          },
  
          cbrt: function cbrt(value) {
              var x = Number(value);
              if (x === 0) { return x; }
              var negate = x < 0;
              var result;
              if (negate) { x = -x; }
              if (x === Infinity) {
                  result = Infinity;
              } else {
                  result = _exp(_log(x) / 3);
                  // from http://en.wikipedia.org/wiki/Cube_root#Numerical_methods
                  result = ((x / (result * result)) + (2 * result)) / 3;
              }
              return negate ? -result : result;
          },
  
          clz32: function clz32(value) {
              // See https://bugs.ecmascript.org/show_bug.cgi?id=2465
              var x = Number(value);
              var number = ES.ToUint32(x);
              if (number === 0) {
                  return 32;
              }
              return numberCLZ ? ES.Call(numberCLZ, number) : 31 - _floor(_log(number + 0.5) * LOG2E);
          },
  
          cosh: function cosh(value) {
              var x = Number(value);
              if (x === 0) { return 1; } // +0 or -0
              if (numberIsNaN(x)) { return NaN; }
              if (!globalIsFinite(x)) { return Infinity; }
  
              var t = _exp(_abs(x) - 1);
              return (t + (1 / (t * E * E))) * (E / 2);
          },
  
          expm1: function expm1(value) {
              var x = Number(value);
              if (x === -Infinity) { return -1; }
              if (!globalIsFinite(x) || x === 0) { return x; }
              if (_abs(x) > 0.5) {
                  return _exp(x) - 1;
              }
              // A more precise approximation using Taylor series expansion
              // from https://github.com/paulmillr/es6-shim/issues/314#issuecomment-70293986
              var t = x;
              var sum = 0;
              var n = 1;
              while (sum + t !== sum) {
                  sum += t;
                  n += 1;
                  t *= x / n;
              }
              return sum;
          },
  
          hypot: function hypot(x, y) {
              var result = 0;
              var largest = 0;
              for (var i = 0; i < arguments.length; ++i) {
                  var value = _abs(Number(arguments[i]));
                  if (largest < value) {
                      result *= (largest / value) * (largest / value);
                      result += 1;
                      largest = value;
                  } else {
                      result += value > 0 ? (value / largest) * (value / largest) : value;
                  }
              }
              return largest === Infinity ? Infinity : largest * _sqrt(result);
          },
  
          log2: function log2(value) {
              return _log(value) * LOG2E;
          },
  
          log10: function log10(value) {
              return _log(value) * LOG10E;
          },
  
          log1p: _log1p,
  
          sign: _sign,
  
          sinh: function sinh(value) {
              var x = Number(value);
              if (!globalIsFinite(x) || x === 0) { return x; }
  
              var a = _abs(x);
              if (a < 1) {
                  var u = Math.expm1(a);
                  return _sign(x) * u * (1 + (1 / (u + 1))) / 2;
              }
              var t = _exp(a - 1);
              return _sign(x) * (t - (1 / (t * E * E))) * (E / 2);
          },
  
          tanh: function tanh(value) {
              var x = Number(value);
              if (numberIsNaN(x) || x === 0) { return x; }
              // can exit early at +-20 as JS loses precision for true value at this integer
              if (x >= 20) { return 1; }
              if (x <= -20) { return -1; }
  
              return (Math.expm1(x) - Math.expm1(-x)) / (_exp(x) + _exp(-x));
          },
  
          trunc: function trunc(value) {
              var x = Number(value);
              return x < 0 ? -_floor(-x) : _floor(x);
          },
  
          imul: function imul(x, y) {
              // taken from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/imul
              var a = ES.ToUint32(x);
              var b = ES.ToUint32(y);
              var ah = (a >>> 16) & 0xffff;
              var al = a & 0xffff;
              var bh = (b >>> 16) & 0xffff;
              var bl = b & 0xffff;
              // the shift by 0 fixes the sign on the high part
              // the final |0 converts the unsigned value into a signed value
              return (al * bl) + ((((ah * bl) + (al * bh)) << 16) >>> 0) | 0;
          },
  
          fround: function fround(x) {
              var v = Number(x);
              if (v === 0 || v === Infinity || v === -Infinity || numberIsNaN(v)) {
                  return v;
              }
              var sign = _sign(v);
              var abs = _abs(v);
              if (abs < BINARY_32_MIN_VALUE) {
                  return sign * roundTiesToEven(
                          abs / BINARY_32_MIN_VALUE / BINARY_32_EPSILON
                      ) * BINARY_32_MIN_VALUE * BINARY_32_EPSILON;
              }
              // Veltkamp's splitting (?)
              var a = (1 + (BINARY_32_EPSILON / Number.EPSILON)) * abs;
              var result = a - (a - abs);
              if (result > BINARY_32_MAX_VALUE || numberIsNaN(result)) {
                  return sign * Infinity;
              }
              return sign * result;
          }
      };
  
      var withinULPDistance = function withinULPDistance(result, expected, distance) {
          return _abs(1 - (result / expected)) / Number.EPSILON < (distance || 8);
      };
  
      defineProperties(Math, MathShims);
      // Chrome < 40 sinh returns ∞ for large numbers
      defineProperty(Math, 'sinh', MathShims.sinh, Math.sinh(710) === Infinity);
      // Chrome < 40 cosh returns ∞ for large numbers
      defineProperty(Math, 'cosh', MathShims.cosh, Math.cosh(710) === Infinity);
      // IE 11 TP has an imprecise log1p: reports Math.log1p(-1e-17) as 0
      defineProperty(Math, 'log1p', MathShims.log1p, Math.log1p(-1e-17) !== -1e-17);
      // IE 11 TP has an imprecise asinh: reports Math.asinh(-1e7) as not exactly equal to -Math.asinh(1e7)
      defineProperty(Math, 'asinh', MathShims.asinh, Math.asinh(-1e7) !== -Math.asinh(1e7));
      // Chrome < 54 asinh returns ∞ for large numbers and should not
      defineProperty(Math, 'asinh', MathShims.asinh, Math.asinh(1e+300) === Infinity);
      // Chrome < 54 atanh incorrectly returns 0 for large numbers
      defineProperty(Math, 'atanh', MathShims.atanh, Math.atanh(1e-300) === 0);
      // Chrome 40 has an imprecise Math.tanh with very small numbers
      defineProperty(Math, 'tanh', MathShims.tanh, Math.tanh(-2e-17) !== -2e-17);
      // Chrome 40 loses Math.acosh precision with high numbers
      defineProperty(Math, 'acosh', MathShims.acosh, Math.acosh(Number.MAX_VALUE) === Infinity);
      // Chrome < 54 has an inaccurate acosh for EPSILON deltas
      defineProperty(Math, 'acosh', MathShims.acosh, !withinULPDistance(Math.acosh(1 + Number.EPSILON), Math.sqrt(2 * Number.EPSILON)));
      // Firefox 38 on Windows
      defineProperty(Math, 'cbrt', MathShims.cbrt, !withinULPDistance(Math.cbrt(1e-300), 1e-100));
      // node 0.11 has an imprecise Math.sinh with very small numbers
      defineProperty(Math, 'sinh', MathShims.sinh, Math.sinh(-2e-17) !== -2e-17);
      // FF 35 on Linux reports 22025.465794806725 for Math.expm1(10)
      var expm1OfTen = Math.expm1(10);
      defineProperty(Math, 'expm1', MathShims.expm1, expm1OfTen > 22025.465794806719 || expm1OfTen < 22025.4657948067165168);
  
      var origMathRound = Math.round;
      // breaks in e.g. Safari 8, Internet Explorer 11, Opera 12
      var roundHandlesBoundaryConditions = Math.round(0.5 - (Number.EPSILON / 4)) === 0 &&
          Math.round(-0.5 + (Number.EPSILON / 3.99)) === 1;
  
      // When engines use Math.floor(x + 0.5) internally, Math.round can be buggy for large integers.
      // This behavior should be governed by "round to nearest, ties to even mode"
      // see http://www.ecma-international.org/ecma-262/6.0/#sec-terms-and-definitions-number-type
      // These are the boundary cases where it breaks.
      var smallestPositiveNumberWhereRoundBreaks = inverseEpsilon + 1;
      var largestPositiveNumberWhereRoundBreaks = (2 * inverseEpsilon) - 1;
      var roundDoesNotIncreaseIntegers = [
          smallestPositiveNumberWhereRoundBreaks,
          largestPositiveNumberWhereRoundBreaks
      ].every(function (num) {
          return Math.round(num) === num;
      });
      defineProperty(Math, 'round', function round(x) {
          var floor = _floor(x);
          var ceil = floor === -1 ? -0 : floor + 1;
          return x - floor < 0.5 ? floor : ceil;
      }, !roundHandlesBoundaryConditions || !roundDoesNotIncreaseIntegers);
      Value.preserveToString(Math.round, origMathRound);
  
      var origImul = Math.imul;
      if (Math.imul(0xffffffff, 5) !== -5) {
          // Safari 6.1, at least, reports "0" for this value
          Math.imul = MathShims.imul;
          Value.preserveToString(Math.imul, origImul);
      }
      if (Math.imul.length !== 2) {
          // Safari 8.0.4 has a length of 1
          // fixed in https://bugs.webkit.org/show_bug.cgi?id=143658
          overrideNative(Math, 'imul', function imul(x, y) {
              return ES.Call(origImul, Math, arguments);
          });
      }
  
      // Promises
      // Simplest possible implementation; use a 3rd-party library if you
      // want the best possible speed and/or long stack traces.
      var PromiseShim = (function () {
          var setTimeout = globals.setTimeout;
          // some environments don't have setTimeout - no way to shim here.
          if (typeof setTimeout !== 'function' && typeof setTimeout !== 'object') { return; }
  
          ES.IsPromise = function (promise) {
              if (!ES.TypeIsObject(promise)) {
                  return false;
              }
              if (typeof promise._promise === 'undefined') {
                  return false; // uninitialized, or missing our hidden field.
              }
              return true;
          };
  
          // "PromiseCapability" in the spec is what most promise implementations
          // call a "deferred".
          var PromiseCapability = function (C) {
              if (!ES.IsConstructor(C)) {
                  throw new TypeError('Bad promise constructor');
              }
              var capability = this;
              var resolver = function (resolve, reject) {
                  if (capability.resolve !== void 0 || capability.reject !== void 0) {
                      throw new TypeError('Bad Promise implementation!');
                  }
                  capability.resolve = resolve;
                  capability.reject = reject;
              };
              // Initialize fields to inform optimizers about the object shape.
              capability.resolve = void 0;
              capability.reject = void 0;
              capability.promise = new C(resolver);
              if (!(ES.IsCallable(capability.resolve) && ES.IsCallable(capability.reject))) {
                  throw new TypeError('Bad promise constructor');
              }
          };
  
          // find an appropriate setImmediate-alike
          var makeZeroTimeout;
          /*global window */
          if (typeof window !== 'undefined' && ES.IsCallable(window.postMessage)) {
              makeZeroTimeout = function () {
                  // from http://dbaron.org/log/20100309-faster-timeouts
                  var timeouts = [];
                  var messageName = 'zero-timeout-message';
                  var setZeroTimeout = function (fn) {
                      _push(timeouts, fn);
                      window.postMessage(messageName, '*');
                  };
                  var handleMessage = function (event) {
                      if (event.source === window && event.data === messageName) {
                          event.stopPropagation();
                          if (timeouts.length === 0) { return; }
                          var fn = _shift(timeouts);
                          fn();
                      }
                  };
                  window.addEventListener('message', handleMessage, true);
                  return setZeroTimeout;
              };
          }
          var makePromiseAsap = function () {
              // An efficient task-scheduler based on a pre-existing Promise
              // implementation, which we can use even if we override the
              // global Promise below (in order to workaround bugs)
              // https://github.com/Raynos/observ-hash/issues/2#issuecomment-35857671
              var P = globals.Promise;
              var pr = P && P.resolve && P.resolve();
              return pr && function (task) {
                      return pr.then(task);
                  };
          };
          /*global process */
          /* jscs:disable disallowMultiLineTernary */
          var enqueue = ES.IsCallable(globals.setImmediate) ?
              globals.setImmediate :
              typeof process === 'object' && process.nextTick ? process.nextTick :
                  makePromiseAsap() ||
                  (ES.IsCallable(makeZeroTimeout) ? makeZeroTimeout() :
                      function (task) { setTimeout(task, 0); }); // fallback
          /* jscs:enable disallowMultiLineTernary */
  
          // Constants for Promise implementation
          var PROMISE_IDENTITY = function (x) { return x; };
          var PROMISE_THROWER = function (e) { throw e; };
          var PROMISE_PENDING = 0;
          var PROMISE_FULFILLED = 1;
          var PROMISE_REJECTED = 2;
          // We store fulfill/reject handlers and capabilities in a single array.
          var PROMISE_FULFILL_OFFSET = 0;
          var PROMISE_REJECT_OFFSET = 1;
          var PROMISE_CAPABILITY_OFFSET = 2;
          // This is used in an optimization for chaining promises via then.
          var PROMISE_FAKE_CAPABILITY = {};
  
          var enqueuePromiseReactionJob = function (handler, capability, argument) {
              enqueue(function () {
                  promiseReactionJob(handler, capability, argument);
              });
          };
  
          var promiseReactionJob = function (handler, promiseCapability, argument) {
              var handlerResult, f;
              if (promiseCapability === PROMISE_FAKE_CAPABILITY) {
                  // Fast case, when we don't actually need to chain through to a
                  // (real) promiseCapability.
                  return handler(argument);
              }
              try {
                  handlerResult = handler(argument);
                  f = promiseCapability.resolve;
              } catch (e) {
                  handlerResult = e;
                  f = promiseCapability.reject;
              }
              f(handlerResult);
          };
  
          var fulfillPromise = function (promise, value) {
              var _promise = promise._promise;
              var length = _promise.reactionLength;
              if (length > 0) {
                  enqueuePromiseReactionJob(
                      _promise.fulfillReactionHandler0,
                      _promise.reactionCapability0,
                      value
                  );
                  _promise.fulfillReactionHandler0 = void 0;
                  _promise.rejectReactions0 = void 0;
                  _promise.reactionCapability0 = void 0;
                  if (length > 1) {
                      for (var i = 1, idx = 0; i < length; i++, idx += 3) {
                          enqueuePromiseReactionJob(
                              _promise[idx + PROMISE_FULFILL_OFFSET],
                              _promise[idx + PROMISE_CAPABILITY_OFFSET],
                              value
                          );
                          promise[idx + PROMISE_FULFILL_OFFSET] = void 0;
                          promise[idx + PROMISE_REJECT_OFFSET] = void 0;
                          promise[idx + PROMISE_CAPABILITY_OFFSET] = void 0;
                      }
                  }
              }
              _promise.result = value;
              _promise.state = PROMISE_FULFILLED;
              _promise.reactionLength = 0;
          };
  
          var rejectPromise = function (promise, reason) {
              var _promise = promise._promise;
              var length = _promise.reactionLength;
              if (length > 0) {
                  enqueuePromiseReactionJob(
                      _promise.rejectReactionHandler0,
                      _promise.reactionCapability0,
                      reason
                  );
                  _promise.fulfillReactionHandler0 = void 0;
                  _promise.rejectReactions0 = void 0;
                  _promise.reactionCapability0 = void 0;
                  if (length > 1) {
                      for (var i = 1, idx = 0; i < length; i++, idx += 3) {
                          enqueuePromiseReactionJob(
                              _promise[idx + PROMISE_REJECT_OFFSET],
                              _promise[idx + PROMISE_CAPABILITY_OFFSET],
                              reason
                          );
                          promise[idx + PROMISE_FULFILL_OFFSET] = void 0;
                          promise[idx + PROMISE_REJECT_OFFSET] = void 0;
                          promise[idx + PROMISE_CAPABILITY_OFFSET] = void 0;
                      }
                  }
              }
              _promise.result = reason;
              _promise.state = PROMISE_REJECTED;
              _promise.reactionLength = 0;
          };
  
          var createResolvingFunctions = function (promise) {
              var alreadyResolved = false;
              var resolve = function (resolution) {
                  var then;
                  if (alreadyResolved) { return; }
                  alreadyResolved = true;
                  if (resolution === promise) {
                      return rejectPromise(promise, new TypeError('Self resolution'));
                  }
                  if (!ES.TypeIsObject(resolution)) {
                      return fulfillPromise(promise, resolution);
                  }
                  try {
                      then = resolution.then;
                  } catch (e) {
                      return rejectPromise(promise, e);
                  }
                  if (!ES.IsCallable(then)) {
                      return fulfillPromise(promise, resolution);
                  }
                  enqueue(function () {
                      promiseResolveThenableJob(promise, resolution, then);
                  });
              };
              var reject = function (reason) {
                  if (alreadyResolved) { return; }
                  alreadyResolved = true;
                  return rejectPromise(promise, reason);
              };
              return { resolve: resolve, reject: reject };
          };
  
          var optimizedThen = function (then, thenable, resolve, reject) {
              // Optimization: since we discard the result, we can pass our
              // own then implementation a special hint to let it know it
              // doesn't have to create it.  (The PROMISE_FAKE_CAPABILITY
              // object is local to this implementation and unforgeable outside.)
              if (then === Promise$prototype$then) {
                  _call(then, thenable, resolve, reject, PROMISE_FAKE_CAPABILITY);
              } else {
                  _call(then, thenable, resolve, reject);
              }
          };
          var promiseResolveThenableJob = function (promise, thenable, then) {
              var resolvingFunctions = createResolvingFunctions(promise);
              var resolve = resolvingFunctions.resolve;
              var reject = resolvingFunctions.reject;
              try {
                  optimizedThen(then, thenable, resolve, reject);
              } catch (e) {
                  reject(e);
              }
          };
  
          var Promise$prototype, Promise$prototype$then;
          var Promise = (function () {
              var PromiseShim = function Promise(resolver) {
                  if (!(this instanceof PromiseShim)) {
                      throw new TypeError('Constructor Promise requires "new"');
                  }
                  if (this && this._promise) {
                      throw new TypeError('Bad construction');
                  }
                  // see https://bugs.ecmascript.org/show_bug.cgi?id=2482
                  if (!ES.IsCallable(resolver)) {
                      throw new TypeError('not a valid resolver');
                  }
                  var promise = emulateES6construct(this, PromiseShim, Promise$prototype, {
                      _promise: {
                          result: void 0,
                          state: PROMISE_PENDING,
                          // The first member of the "reactions" array is inlined here,
                          // since most promises only have one reaction.
                          // We've also exploded the 'reaction' object to inline the
                          // "handler" and "capability" fields, since both fulfill and
                          // reject reactions share the same capability.
                          reactionLength: 0,
                          fulfillReactionHandler0: void 0,
                          rejectReactionHandler0: void 0,
                          reactionCapability0: void 0
                      }
                  });
                  var resolvingFunctions = createResolvingFunctions(promise);
                  var reject = resolvingFunctions.reject;
                  try {
                      resolver(resolvingFunctions.resolve, reject);
                  } catch (e) {
                      reject(e);
                  }
                  return promise;
              };
              return PromiseShim;
          }());
          Promise$prototype = Promise.prototype;
  
          var _promiseAllResolver = function (index, values, capability, remaining) {
              var alreadyCalled = false;
              return function (x) {
                  if (alreadyCalled) { return; }
                  alreadyCalled = true;
                  values[index] = x;
                  if ((--remaining.count) === 0) {
                      var resolve = capability.resolve;
                      resolve(values); // call w/ this===undefined
                  }
              };
          };
  
          var performPromiseAll = function (iteratorRecord, C, resultCapability) {
              var it = iteratorRecord.iterator;
              var values = [];
              var remaining = { count: 1 };
              var next, nextValue;
              var index = 0;
              while (true) {
                  try {
                      next = ES.IteratorStep(it);
                      if (next === false) {
                          iteratorRecord.done = true;
                          break;
                      }
                      nextValue = next.value;
                  } catch (e) {
                      iteratorRecord.done = true;
                      throw e;
                  }
                  values[index] = void 0;
                  var nextPromise = C.resolve(nextValue);
                  var resolveElement = _promiseAllResolver(
                      index, values, resultCapability, remaining
                  );
                  remaining.count += 1;
                  optimizedThen(nextPromise.then, nextPromise, resolveElement, resultCapability.reject);
                  index += 1;
              }
              if ((--remaining.count) === 0) {
                  var resolve = resultCapability.resolve;
                  resolve(values); // call w/ this===undefined
              }
              return resultCapability.promise;
          };
  
          var performPromiseRace = function (iteratorRecord, C, resultCapability) {
              var it = iteratorRecord.iterator;
              var next, nextValue, nextPromise;
              while (true) {
                  try {
                      next = ES.IteratorStep(it);
                      if (next === false) {
                          // NOTE: If iterable has no items, resulting promise will never
                          // resolve; see:
                          // https://github.com/domenic/promises-unwrapping/issues/75
                          // https://bugs.ecmascript.org/show_bug.cgi?id=2515
                          iteratorRecord.done = true;
                          break;
                      }
                      nextValue = next.value;
                  } catch (e) {
                      iteratorRecord.done = true;
                      throw e;
                  }
                  nextPromise = C.resolve(nextValue);
                  optimizedThen(nextPromise.then, nextPromise, resultCapability.resolve, resultCapability.reject);
              }
              return resultCapability.promise;
          };
  
          defineProperties(Promise, {
              all: function all(iterable) {
                  var C = this;
                  if (!ES.TypeIsObject(C)) {
                      throw new TypeError('Promise is not object');
                  }
                  var capability = new PromiseCapability(C);
                  var iterator, iteratorRecord;
                  try {
                      iterator = ES.GetIterator(iterable);
                      iteratorRecord = { iterator: iterator, done: false };
                      return performPromiseAll(iteratorRecord, C, capability);
                  } catch (e) {
                      var exception = e;
                      if (iteratorRecord && !iteratorRecord.done) {
                          try {
                              ES.IteratorClose(iterator, true);
                          } catch (ee) {
                              exception = ee;
                          }
                      }
                      var reject = capability.reject;
                      reject(exception);
                      return capability.promise;
                  }
              },
  
              race: function race(iterable) {
                  var C = this;
                  if (!ES.TypeIsObject(C)) {
                      throw new TypeError('Promise is not object');
                  }
                  var capability = new PromiseCapability(C);
                  var iterator, iteratorRecord;
                  try {
                      iterator = ES.GetIterator(iterable);
                      iteratorRecord = { iterator: iterator, done: false };
                      return performPromiseRace(iteratorRecord, C, capability);
                  } catch (e) {
                      var exception = e;
                      if (iteratorRecord && !iteratorRecord.done) {
                          try {
                              ES.IteratorClose(iterator, true);
                          } catch (ee) {
                              exception = ee;
                          }
                      }
                      var reject = capability.reject;
                      reject(exception);
                      return capability.promise;
                  }
              },
  
              reject: function reject(reason) {
                  var C = this;
                  if (!ES.TypeIsObject(C)) {
                      throw new TypeError('Bad promise constructor');
                  }
                  var capability = new PromiseCapability(C);
                  var rejectFunc = capability.reject;
                  rejectFunc(reason); // call with this===undefined
                  return capability.promise;
              },
  
              resolve: function resolve(v) {
                  // See https://esdiscuss.org/topic/fixing-promise-resolve for spec
                  var C = this;
                  if (!ES.TypeIsObject(C)) {
                      throw new TypeError('Bad promise constructor');
                  }
                  if (ES.IsPromise(v)) {
                      var constructor = v.constructor;
                      if (constructor === C) {
                          return v;
                      }
                  }
                  var capability = new PromiseCapability(C);
                  var resolveFunc = capability.resolve;
                  resolveFunc(v); // call with this===undefined
                  return capability.promise;
              }
          });
  
          defineProperties(Promise$prototype, {
              'catch': function (onRejected) {
                  return this.then(null, onRejected);
              },
  
              then: function then(onFulfilled, onRejected) {
                  var promise = this;
                  if (!ES.IsPromise(promise)) { throw new TypeError('not a promise'); }
                  var C = ES.SpeciesConstructor(promise, Promise);
                  var resultCapability;
                  var returnValueIsIgnored = arguments.length > 2 && arguments[2] === PROMISE_FAKE_CAPABILITY;
                  if (returnValueIsIgnored && C === Promise) {
                      resultCapability = PROMISE_FAKE_CAPABILITY;
                  } else {
                      resultCapability = new PromiseCapability(C);
                  }
                  // PerformPromiseThen(promise, onFulfilled, onRejected, resultCapability)
                  // Note that we've split the 'reaction' object into its two
                  // components, "capabilities" and "handler"
                  // "capabilities" is always equal to `resultCapability`
                  var fulfillReactionHandler = ES.IsCallable(onFulfilled) ? onFulfilled : PROMISE_IDENTITY;
                  var rejectReactionHandler = ES.IsCallable(onRejected) ? onRejected : PROMISE_THROWER;
                  var _promise = promise._promise;
                  var value;
                  if (_promise.state === PROMISE_PENDING) {
                      if (_promise.reactionLength === 0) {
                          _promise.fulfillReactionHandler0 = fulfillReactionHandler;
                          _promise.rejectReactionHandler0 = rejectReactionHandler;
                          _promise.reactionCapability0 = resultCapability;
                      } else {
                          var idx = 3 * (_promise.reactionLength - 1);
                          _promise[idx + PROMISE_FULFILL_OFFSET] = fulfillReactionHandler;
                          _promise[idx + PROMISE_REJECT_OFFSET] = rejectReactionHandler;
                          _promise[idx + PROMISE_CAPABILITY_OFFSET] = resultCapability;
                      }
                      _promise.reactionLength += 1;
                  } else if (_promise.state === PROMISE_FULFILLED) {
                      value = _promise.result;
                      enqueuePromiseReactionJob(
                          fulfillReactionHandler, resultCapability, value
                      );
                  } else if (_promise.state === PROMISE_REJECTED) {
                      value = _promise.result;
                      enqueuePromiseReactionJob(
                          rejectReactionHandler, resultCapability, value
                      );
                  } else {
                      throw new TypeError('unexpected Promise state');
                  }
                  return resultCapability.promise;
              }
          });
          // This helps the optimizer by ensuring that methods which take
          // capabilities aren't polymorphic.
          PROMISE_FAKE_CAPABILITY = new PromiseCapability(Promise);
          Promise$prototype$then = Promise$prototype.then;
  
          return Promise;
      }());
  
      // Chrome's native Promise has extra methods that it shouldn't have. Let's remove them.
      if (globals.Promise) {
          delete globals.Promise.accept;
          delete globals.Promise.defer;
          delete globals.Promise.prototype.chain;
      }
  
      if (typeof PromiseShim === 'function') {
          // export the Promise constructor.
          defineProperties(globals, { Promise: PromiseShim });
          // In Chrome 33 (and thereabouts) Promise is defined, but the
          // implementation is buggy in a number of ways.  Let's check subclassing
          // support to see if we have a buggy implementation.
          var promiseSupportsSubclassing = supportsSubclassing(globals.Promise, function (S) {
              return S.resolve(42).then(function () {}) instanceof S;
          });
          var promiseIgnoresNonFunctionThenCallbacks = !throwsError(function () {
              globals.Promise.reject(42).then(null, 5).then(null, noop);
          });
          var promiseRequiresObjectContext = throwsError(function () { globals.Promise.call(3, noop); });
          // Promise.resolve() was errata'ed late in the ES6 process.
          // See: https://bugzilla.mozilla.org/show_bug.cgi?id=1170742
          //      https://code.google.com/p/v8/issues/detail?id=4161
          // It serves as a proxy for a number of other bugs in early Promise
          // implementations.
          var promiseResolveBroken = (function (Promise) {
              var p = Promise.resolve(5);
              p.constructor = {};
              var p2 = Promise.resolve(p);
              try {
                  p2.then(null, noop).then(null, noop); // avoid "uncaught rejection" warnings in console
              } catch (e) {
                  return true; // v8 native Promises break here https://code.google.com/p/chromium/issues/detail?id=575314
              }
              return p === p2; // This *should* be false!
          }(globals.Promise));
  
          // Chrome 46 (probably older too) does not retrieve a thenable's .then synchronously
          var getsThenSynchronously = supportsDescriptors && (function () {
                  var count = 0;
                  var thenable = Object.defineProperty({}, 'then', { get: function () { count += 1; } });
                  Promise.resolve(thenable);
                  return count === 1;
              }());
  
          var BadResolverPromise = function BadResolverPromise(executor) {
              var p = new Promise(executor);
              executor(3, function () {});
              this.then = p.then;
              this.constructor = BadResolverPromise;
          };
          BadResolverPromise.prototype = Promise.prototype;
          BadResolverPromise.all = Promise.all;
          // Chrome Canary 49 (probably older too) has some implementation bugs
          var hasBadResolverPromise = valueOrFalseIfThrows(function () {
              return !!BadResolverPromise.all([1, 2]);
          });
  
          if (!promiseSupportsSubclassing || !promiseIgnoresNonFunctionThenCallbacks ||
              !promiseRequiresObjectContext || promiseResolveBroken ||
              !getsThenSynchronously || hasBadResolverPromise) {
              /* globals Promise: true */
              /* eslint-disable no-undef, no-global-assign */
              /* jshint -W020 */
              Promise = PromiseShim;
              /* jshint +W020 */
              /* eslint-enable no-undef, no-global-assign */
              /* globals Promise: false */
              overrideNative(globals, 'Promise', PromiseShim);
          }
          if (Promise.all.length !== 1) {
              var origAll = Promise.all;
              overrideNative(Promise, 'all', function all(iterable) {
                  return ES.Call(origAll, this, arguments);
              });
          }
          if (Promise.race.length !== 1) {
              var origRace = Promise.race;
              overrideNative(Promise, 'race', function race(iterable) {
                  return ES.Call(origRace, this, arguments);
              });
          }
          if (Promise.resolve.length !== 1) {
              var origResolve = Promise.resolve;
              overrideNative(Promise, 'resolve', function resolve(x) {
                  return ES.Call(origResolve, this, arguments);
              });
          }
          if (Promise.reject.length !== 1) {
              var origReject = Promise.reject;
              overrideNative(Promise, 'reject', function reject(r) {
                  return ES.Call(origReject, this, arguments);
              });
          }
          ensureEnumerable(Promise, 'all');
          ensureEnumerable(Promise, 'race');
          ensureEnumerable(Promise, 'resolve');
          ensureEnumerable(Promise, 'reject');
          addDefaultSpecies(Promise);
      }
  
      // Map and Set require a true ES5 environment
      // Their fast path also requires that the environment preserve
      // property insertion order, which is not guaranteed by the spec.
      var testOrder = function (a) {
          var b = keys(_reduce(a, function (o, k) {
              o[k] = true;
              return o;
          }, {}));
          return a.join(':') === b.join(':');
      };
      var preservesInsertionOrder = testOrder(['z', 'a', 'bb']);
      // some engines (eg, Chrome) only preserve insertion order for string keys
      var preservesNumericInsertionOrder = testOrder(['z', 1, 'a', '3', 2]);
  
      if (supportsDescriptors) {
  
          var fastkey = function fastkey(key, skipInsertionOrderCheck) {
              if (!skipInsertionOrderCheck && !preservesInsertionOrder) {
                  return null;
              }
              if (isNullOrUndefined(key)) {
                  return '^' + ES.ToString(key);
              } else if (typeof key === 'string') {
                  return '$' + key;
              } else if (typeof key === 'number') {
                  // note that -0 will get coerced to "0" when used as a property key
                  if (!preservesNumericInsertionOrder) {
                      return 'n' + key;
                  }
                  return key;
              } else if (typeof key === 'boolean') {
                  return 'b' + key;
              }
              return null;
          };
  
          var emptyObject = function emptyObject() {
              // accomodate some older not-quite-ES5 browsers
              return Object.create ? Object.create(null) : {};
          };
  
          var addIterableToMap = function addIterableToMap(MapConstructor, map, iterable) {
              if (isArray(iterable) || Type.string(iterable)) {
                  _forEach(iterable, function (entry) {
                      if (!ES.TypeIsObject(entry)) {
                          throw new TypeError('Iterator value ' + entry + ' is not an entry object');
                      }
                      map.set(entry[0], entry[1]);
                  });
              } else if (iterable instanceof MapConstructor) {
                  _call(MapConstructor.prototype.forEach, iterable, function (value, key) {
                      map.set(key, value);
                  });
              } else {
                  var iter, adder;
                  if (!isNullOrUndefined(iterable)) {
                      adder = map.set;
                      if (!ES.IsCallable(adder)) { throw new TypeError('bad map'); }
                      iter = ES.GetIterator(iterable);
                  }
                  if (typeof iter !== 'undefined') {
                      while (true) {
                          var next = ES.IteratorStep(iter);
                          if (next === false) { break; }
                          var nextItem = next.value;
                          try {
                              if (!ES.TypeIsObject(nextItem)) {
                                  throw new TypeError('Iterator value ' + nextItem + ' is not an entry object');
                              }
                              _call(adder, map, nextItem[0], nextItem[1]);
                          } catch (e) {
                              ES.IteratorClose(iter, true);
                              throw e;
                          }
                      }
                  }
              }
          };
          var addIterableToSet = function addIterableToSet(SetConstructor, set, iterable) {
              if (isArray(iterable) || Type.string(iterable)) {
                  _forEach(iterable, function (value) {
                      set.add(value);
                  });
              } else if (iterable instanceof SetConstructor) {
                  _call(SetConstructor.prototype.forEach, iterable, function (value) {
                      set.add(value);
                  });
              } else {
                  var iter, adder;
                  if (!isNullOrUndefined(iterable)) {
                      adder = set.add;
                      if (!ES.IsCallable(adder)) { throw new TypeError('bad set'); }
                      iter = ES.GetIterator(iterable);
                  }
                  if (typeof iter !== 'undefined') {
                      while (true) {
                          var next = ES.IteratorStep(iter);
                          if (next === false) { break; }
                          var nextValue = next.value;
                          try {
                              _call(adder, set, nextValue);
                          } catch (e) {
                              ES.IteratorClose(iter, true);
                              throw e;
                          }
                      }
                  }
              }
          };
  
          var collectionShims = {
              Map: (function () {
  
                  var empty = {};
  
                  var MapEntry = function MapEntry(key, value) {
                      this.key = key;
                      this.value = value;
                      this.next = null;
                      this.prev = null;
                  };
  
                  MapEntry.prototype.isRemoved = function isRemoved() {
                      return this.key === empty;
                  };
  
                  var isMap = function isMap(map) {
                      return !!map._es6map;
                  };
  
                  var requireMapSlot = function requireMapSlot(map, method) {
                      if (!ES.TypeIsObject(map) || !isMap(map)) {
                          throw new TypeError('Method Map.prototype.' + method + ' called on incompatible receiver ' + ES.ToString(map));
                      }
                  };
  
                  var MapIterator = function MapIterator(map, kind) {
                      requireMapSlot(map, '[[MapIterator]]');
                      this.head = map._head;
                      this.i = this.head;
                      this.kind = kind;
                  };
  
                  MapIterator.prototype = {
                      isMapIterator: true,
                      next: function next() {
                          if (!this.isMapIterator) {
                              throw new TypeError('Not a MapIterator');
                          }
                          var i = this.i;
                          var kind = this.kind;
                          var head = this.head;
                          if (typeof this.i === 'undefined') {
                              return iteratorResult();
                          }
                          while (i.isRemoved() && i !== head) {
                              // back up off of removed entries
                              i = i.prev;
                          }
                          // advance to next unreturned element.
                          var result;
                          while (i.next !== head) {
                              i = i.next;
                              if (!i.isRemoved()) {
                                  if (kind === 'key') {
                                      result = i.key;
                                  } else if (kind === 'value') {
                                      result = i.value;
                                  } else {
                                      result = [i.key, i.value];
                                  }
                                  this.i = i;
                                  return iteratorResult(result);
                              }
                          }
                          // once the iterator is done, it is done forever.
                          this.i = void 0;
                          return iteratorResult();
                      }
                  };
                  addIterator(MapIterator.prototype);
  
                  var Map$prototype;
                  var MapShim = function Map() {
                      if (!(this instanceof Map)) {
                          throw new TypeError('Constructor Map requires "new"');
                      }
                      if (this && this._es6map) {
                          throw new TypeError('Bad construction');
                      }
                      var map = emulateES6construct(this, Map, Map$prototype, {
                          _es6map: true,
                          _head: null,
                          _map: OrigMap ? new OrigMap() : null,
                          _size: 0,
                          _storage: emptyObject()
                      });
  
                      var head = new MapEntry(null, null);
                      // circular doubly-linked list.
                      /* eslint no-multi-assign: 1 */
                      head.next = head.prev = head;
                      map._head = head;
  
                      // Optionally initialize map from iterable
                      if (arguments.length > 0) {
                          addIterableToMap(Map, map, arguments[0]);
                      }
                      return map;
                  };
                  Map$prototype = MapShim.prototype;
  
                  Value.getter(Map$prototype, 'size', function () {
                      if (typeof this._size === 'undefined') {
                          throw new TypeError('size method called on incompatible Map');
                      }
                      return this._size;
                  });
  
                  defineProperties(Map$prototype, {
                      get: function get(key) {
                          requireMapSlot(this, 'get');
                          var entry;
                          var fkey = fastkey(key, true);
                          if (fkey !== null) {
                              // fast O(1) path
                              entry = this._storage[fkey];
                              if (entry) {
                                  return entry.value;
                              } else {
                                  return;
                              }
                          }
                          if (this._map) {
                              // fast object key path
                              entry = origMapGet.call(this._map, key);
                              if (entry) {
                                  return entry.value;
                              } else {
                                  return;
                              }
                          }
                          var head = this._head;
                          var i = head;
                          while ((i = i.next) !== head) {
                              if (ES.SameValueZero(i.key, key)) {
                                  return i.value;
                              }
                          }
                      },
  
                      has: function has(key) {
                          requireMapSlot(this, 'has');
                          var fkey = fastkey(key, true);
                          if (fkey !== null) {
                              // fast O(1) path
                              return typeof this._storage[fkey] !== 'undefined';
                          }
                          if (this._map) {
                              // fast object key path
                              return origMapHas.call(this._map, key);
                          }
                          var head = this._head;
                          var i = head;
                          while ((i = i.next) !== head) {
                              if (ES.SameValueZero(i.key, key)) {
                                  return true;
                              }
                          }
                          return false;
                      },
  
                      set: function set(key, value) {
                          requireMapSlot(this, 'set');
                          var head = this._head;
                          var i = head;
                          var entry;
                          var fkey = fastkey(key, true);
                          if (fkey !== null) {
                              // fast O(1) path
                              if (typeof this._storage[fkey] !== 'undefined') {
                                  this._storage[fkey].value = value;
                                  return this;
                              } else {
                                  entry = this._storage[fkey] = new MapEntry(key, value); /* eslint no-multi-assign: 1 */
                                  i = head.prev;
                                  // fall through
                              }
                          } else if (this._map) {
                              // fast object key path
                              if (origMapHas.call(this._map, key)) {
                                  origMapGet.call(this._map, key).value = value;
                              } else {
                                  entry = new MapEntry(key, value);
                                  origMapSet.call(this._map, key, entry);
                                  i = head.prev;
                                  // fall through
                              }
                          }
                          while ((i = i.next) !== head) {
                              if (ES.SameValueZero(i.key, key)) {
                                  i.value = value;
                                  return this;
                              }
                          }
                          entry = entry || new MapEntry(key, value);
                          if (ES.SameValue(-0, key)) {
                              entry.key = +0; // coerce -0 to +0 in entry
                          }
                          entry.next = this._head;
                          entry.prev = this._head.prev;
                          entry.prev.next = entry;
                          entry.next.prev = entry;
                          this._size += 1;
                          return this;
                      },
  
                      'delete': function (key) {
                          requireMapSlot(this, 'delete');
                          var head = this._head;
                          var i = head;
                          var fkey = fastkey(key, true);
                          if (fkey !== null) {
                              // fast O(1) path
                              if (typeof this._storage[fkey] === 'undefined') {
                                  return false;
                              }
                              i = this._storage[fkey].prev;
                              delete this._storage[fkey];
                              // fall through
                          } else if (this._map) {
                              // fast object key path
                              if (!origMapHas.call(this._map, key)) {
                                  return false;
                              }
                              i = origMapGet.call(this._map, key).prev;
                              origMapDelete.call(this._map, key);
                              // fall through
                          }
                          while ((i = i.next) !== head) {
                              if (ES.SameValueZero(i.key, key)) {
                                  i.key = empty;
                                  i.value = empty;
                                  i.prev.next = i.next;
                                  i.next.prev = i.prev;
                                  this._size -= 1;
                                  return true;
                              }
                          }
                          return false;
                      },
  
                      clear: function clear() {
                          /* eslint no-multi-assign: 1 */
                          requireMapSlot(this, 'clear');
                          this._map = OrigMap ? new OrigMap() : null;
                          this._size = 0;
                          this._storage = emptyObject();
                          var head = this._head;
                          var i = head;
                          var p = i.next;
                          while ((i = p) !== head) {
                              i.key = empty;
                              i.value = empty;
                              p = i.next;
                              i.next = i.prev = head;
                          }
                          head.next = head.prev = head;
                      },
  
                      keys: function keys() {
                          requireMapSlot(this, 'keys');
                          return new MapIterator(this, 'key');
                      },
  
                      values: function values() {
                          requireMapSlot(this, 'values');
                          return new MapIterator(this, 'value');
                      },
  
                      entries: function entries() {
                          requireMapSlot(this, 'entries');
                          return new MapIterator(this, 'key+value');
                      },
  
                      forEach: function forEach(callback) {
                          requireMapSlot(this, 'forEach');
                          var context = arguments.length > 1 ? arguments[1] : null;
                          var it = this.entries();
                          for (var entry = it.next(); !entry.done; entry = it.next()) {
                              if (context) {
                                  _call(callback, context, entry.value[1], entry.value[0], this);
                              } else {
                                  callback(entry.value[1], entry.value[0], this);
                              }
                          }
                      }
                  });
                  addIterator(Map$prototype, Map$prototype.entries);
  
                  return MapShim;
              }()),
  
              Set: (function () {
                  var isSet = function isSet(set) {
                      return set._es6set && typeof set._storage !== 'undefined';
                  };
                  var requireSetSlot = function requireSetSlot(set, method) {
                      if (!ES.TypeIsObject(set) || !isSet(set)) {
                          // https://github.com/paulmillr/es6-shim/issues/176
                          throw new TypeError('Set.prototype.' + method + ' called on incompatible receiver ' + ES.ToString(set));
                      }
                  };
  
                  // Creating a Map is expensive.  To speed up the common case of
                  // Sets containing only string or numeric keys, we use an object
                  // as backing storage and lazily create a full Map only when
                  // required.
                  var Set$prototype;
                  var SetShim = function Set() {
                      if (!(this instanceof Set)) {
                          throw new TypeError('Constructor Set requires "new"');
                      }
                      if (this && this._es6set) {
                          throw new TypeError('Bad construction');
                      }
                      var set = emulateES6construct(this, Set, Set$prototype, {
                          _es6set: true,
                          '[[SetData]]': null,
                          _storage: emptyObject()
                      });
                      if (!set._es6set) {
                          throw new TypeError('bad set');
                      }
  
                      // Optionally initialize Set from iterable
                      if (arguments.length > 0) {
                          addIterableToSet(Set, set, arguments[0]);
                      }
                      return set;
                  };
                  Set$prototype = SetShim.prototype;
  
                  var decodeKey = function (key) {
                      var k = key;
                      if (k === '^null') {
                          return null;
                      } else if (k === '^undefined') {
                          return void 0;
                      } else {
                          var first = k.charAt(0);
                          if (first === '$') {
                              return _strSlice(k, 1);
                          } else if (first === 'n') {
                              return +_strSlice(k, 1);
                          } else if (first === 'b') {
                              return k === 'btrue';
                          }
                      }
                      return +k;
                  };
                  // Switch from the object backing storage to a full Map.
                  var ensureMap = function ensureMap(set) {
                      if (!set['[[SetData]]']) {
                          var m = new collectionShims.Map();
                          set['[[SetData]]'] = m;
                          _forEach(keys(set._storage), function (key) {
                              var k = decodeKey(key);
                              m.set(k, k);
                          });
                          set['[[SetData]]'] = m;
                      }
                      set._storage = null; // free old backing storage
                  };
  
                  Value.getter(SetShim.prototype, 'size', function () {
                      requireSetSlot(this, 'size');
                      if (this._storage) {
                          return keys(this._storage).length;
                      }
                      ensureMap(this);
                      return this['[[SetData]]'].size;
                  });
  
                  defineProperties(SetShim.prototype, {
                      has: function has(key) {
                          requireSetSlot(this, 'has');
                          var fkey;
                          if (this._storage && (fkey = fastkey(key)) !== null) {
                              return !!this._storage[fkey];
                          }
                          ensureMap(this);
                          return this['[[SetData]]'].has(key);
                      },
  
                      add: function add(key) {
                          requireSetSlot(this, 'add');
                          var fkey;
                          if (this._storage && (fkey = fastkey(key)) !== null) {
                              this._storage[fkey] = true;
                              return this;
                          }
                          ensureMap(this);
                          this['[[SetData]]'].set(key, key);
                          return this;
                      },
  
                      'delete': function (key) {
                          requireSetSlot(this, 'delete');
                          var fkey;
                          if (this._storage && (fkey = fastkey(key)) !== null) {
                              var hasFKey = _hasOwnProperty(this._storage, fkey);
                              return (delete this._storage[fkey]) && hasFKey;
                          }
                          ensureMap(this);
                          return this['[[SetData]]']['delete'](key);
                      },
  
                      clear: function clear() {
                          requireSetSlot(this, 'clear');
                          if (this._storage) {
                              this._storage = emptyObject();
                          }
                          if (this['[[SetData]]']) {
                              this['[[SetData]]'].clear();
                          }
                      },
  
                      values: function values() {
                          requireSetSlot(this, 'values');
                          ensureMap(this);
                          return new SetIterator(this['[[SetData]]'].values());
                      },
  
                      entries: function entries() {
                          requireSetSlot(this, 'entries');
                          ensureMap(this);
                          return new SetIterator(this['[[SetData]]'].entries());
                      },
  
                      forEach: function forEach(callback) {
                          requireSetSlot(this, 'forEach');
                          var context = arguments.length > 1 ? arguments[1] : null;
                          var entireSet = this;
                          ensureMap(entireSet);
                          this['[[SetData]]'].forEach(function (value, key) {
                              if (context) {
                                  _call(callback, context, key, key, entireSet);
                              } else {
                                  callback(key, key, entireSet);
                              }
                          });
                      }
                  });
                  defineProperty(SetShim.prototype, 'keys', SetShim.prototype.values, true);
                  addIterator(SetShim.prototype, SetShim.prototype.values);
  
                  var SetIterator = function SetIterator(it) {
                      this.it = it;
                  };
                  SetIterator.prototype = {
                      isSetIterator: true,
                      next: function next() {
                          if (!this.isSetIterator) {
                              throw new TypeError('Not a SetIterator');
                          }
                          return this.it.next();
                      }
                  };
                  addIterator(SetIterator.prototype);
  
                  return SetShim;
              }())
          };
  
          var isGoogleTranslate = globals.Set && !Set.prototype['delete'] && Set.prototype.remove && Set.prototype.items && Set.prototype.map && Array.isArray(new Set().keys);
          if (isGoogleTranslate) {
              // special-case force removal of wildly invalid Set implementation in Google Translate iframes
              // see https://github.com/paulmillr/es6-shim/issues/438 / https://twitter.com/ljharb/status/849335573114363904
              globals.Set = collectionShims.Set;
          }
          if (globals.Map || globals.Set) {
              // Safari 8, for example, doesn't accept an iterable.
              var mapAcceptsArguments = valueOrFalseIfThrows(function () { return new Map([[1, 2]]).get(1) === 2; });
              if (!mapAcceptsArguments) {
                  globals.Map = function Map() {
                      if (!(this instanceof Map)) {
                          throw new TypeError('Constructor Map requires "new"');
                      }
                      var m = new OrigMap();
                      if (arguments.length > 0) {
                          addIterableToMap(Map, m, arguments[0]);
                      }
                      delete m.constructor;
                      Object.setPrototypeOf(m, globals.Map.prototype);
                      return m;
                  };
                  globals.Map.prototype = create(OrigMap.prototype);
                  defineProperty(globals.Map.prototype, 'constructor', globals.Map, true);
                  Value.preserveToString(globals.Map, OrigMap);
              }
              var testMap = new Map();
              var mapUsesSameValueZero = (function () {
                  // Chrome 38-42, node 0.11/0.12, iojs 1/2 also have a bug when the Map has a size > 4
                  var m = new Map([[1, 0], [2, 0], [3, 0], [4, 0]]);
                  m.set(-0, m);
                  return m.get(0) === m && m.get(-0) === m && m.has(0) && m.has(-0);
              }());
              var mapSupportsChaining = testMap.set(1, 2) === testMap;
              if (!mapUsesSameValueZero || !mapSupportsChaining) {
                  overrideNative(Map.prototype, 'set', function set(k, v) {
                      _call(origMapSet, this, k === 0 ? 0 : k, v);
                      return this;
                  });
              }
              if (!mapUsesSameValueZero) {
                  defineProperties(Map.prototype, {
                      get: function get(k) {
                          return _call(origMapGet, this, k === 0 ? 0 : k);
                      },
                      has: function has(k) {
                          return _call(origMapHas, this, k === 0 ? 0 : k);
                      }
                  }, true);
                  Value.preserveToString(Map.prototype.get, origMapGet);
                  Value.preserveToString(Map.prototype.has, origMapHas);
              }
              var testSet = new Set();
              var setUsesSameValueZero = Set.prototype['delete'] && Set.prototype.add && Set.prototype.has && (function (s) {
                      s['delete'](0);
                      s.add(-0);
                      return !s.has(0);
                  }(testSet));
              var setSupportsChaining = testSet.add(1) === testSet;
              if (!setUsesSameValueZero || !setSupportsChaining) {
                  var origSetAdd = Set.prototype.add;
                  Set.prototype.add = function add(v) {
                      _call(origSetAdd, this, v === 0 ? 0 : v);
                      return this;
                  };
                  Value.preserveToString(Set.prototype.add, origSetAdd);
              }
              if (!setUsesSameValueZero) {
                  var origSetHas = Set.prototype.has;
                  Set.prototype.has = function has(v) {
                      return _call(origSetHas, this, v === 0 ? 0 : v);
                  };
                  Value.preserveToString(Set.prototype.has, origSetHas);
                  var origSetDel = Set.prototype['delete'];
                  Set.prototype['delete'] = function SetDelete(v) {
                      return _call(origSetDel, this, v === 0 ? 0 : v);
                  };
                  Value.preserveToString(Set.prototype['delete'], origSetDel);
              }
              var mapSupportsSubclassing = supportsSubclassing(globals.Map, function (M) {
                  var m = new M([]);
                  // Firefox 32 is ok with the instantiating the subclass but will
                  // throw when the map is used.
                  m.set(42, 42);
                  return m instanceof M;
              });
              // without Object.setPrototypeOf, subclassing is not possible
              var mapFailsToSupportSubclassing = Object.setPrototypeOf && !mapSupportsSubclassing;
              var mapRequiresNew = (function () {
                  try {
                      return !(globals.Map() instanceof globals.Map);
                  } catch (e) {
                      return e instanceof TypeError;
                  }
              }());
              if (globals.Map.length !== 0 || mapFailsToSupportSubclassing || !mapRequiresNew) {
                  globals.Map = function Map() {
                      if (!(this instanceof Map)) {
                          throw new TypeError('Constructor Map requires "new"');
                      }
                      var m = new OrigMap();
                      if (arguments.length > 0) {
                          addIterableToMap(Map, m, arguments[0]);
                      }
                      delete m.constructor;
                      Object.setPrototypeOf(m, Map.prototype);
                      return m;
                  };
                  globals.Map.prototype = OrigMap.prototype;
                  defineProperty(globals.Map.prototype, 'constructor', globals.Map, true);
                  Value.preserveToString(globals.Map, OrigMap);
              }
              var setSupportsSubclassing = supportsSubclassing(globals.Set, function (S) {
                  var s = new S([]);
                  s.add(42, 42);
                  return s instanceof S;
              });
              // without Object.setPrototypeOf, subclassing is not possible
              var setFailsToSupportSubclassing = Object.setPrototypeOf && !setSupportsSubclassing;
              var setRequiresNew = (function () {
                  try {
                      return !(globals.Set() instanceof globals.Set);
                  } catch (e) {
                      return e instanceof TypeError;
                  }
              }());
              if (globals.Set.length !== 0 || setFailsToSupportSubclassing || !setRequiresNew) {
                  var OrigSet = globals.Set;
                  globals.Set = function Set() {
                      if (!(this instanceof Set)) {
                          throw new TypeError('Constructor Set requires "new"');
                      }
                      var s = new OrigSet();
                      if (arguments.length > 0) {
                          addIterableToSet(Set, s, arguments[0]);
                      }
                      delete s.constructor;
                      Object.setPrototypeOf(s, Set.prototype);
                      return s;
                  };
                  globals.Set.prototype = OrigSet.prototype;
                  defineProperty(globals.Set.prototype, 'constructor', globals.Set, true);
                  Value.preserveToString(globals.Set, OrigSet);
              }
              var newMap = new globals.Map();
              var mapIterationThrowsStopIterator = !valueOrFalseIfThrows(function () {
                  return newMap.keys().next().done;
              });
              /*
               - In Firefox < 23, Map#size is a function.
               - In all current Firefox, Set#entries/keys/values & Map#clear do not exist
               - https://bugzilla.mozilla.org/show_bug.cgi?id=869996
               - In Firefox 24, Map and Set do not implement forEach
               - In Firefox 25 at least, Map and Set are callable without "new"
               */
              if (
                  typeof globals.Map.prototype.clear !== 'function' ||
                  new globals.Set().size !== 0 ||
                  newMap.size !== 0 ||
                  typeof globals.Map.prototype.keys !== 'function' ||
                  typeof globals.Set.prototype.keys !== 'function' ||
                  typeof globals.Map.prototype.forEach !== 'function' ||
                  typeof globals.Set.prototype.forEach !== 'function' ||
                  isCallableWithoutNew(globals.Map) ||
                  isCallableWithoutNew(globals.Set) ||
                  typeof newMap.keys().next !== 'function' || // Safari 8
                  mapIterationThrowsStopIterator || // Firefox 25
                  !mapSupportsSubclassing
              ) {
                  defineProperties(globals, {
                      Map: collectionShims.Map,
                      Set: collectionShims.Set
                  }, true);
              }
  
              if (globals.Set.prototype.keys !== globals.Set.prototype.values) {
                  // Fixed in WebKit with https://bugs.webkit.org/show_bug.cgi?id=144190
                  defineProperty(globals.Set.prototype, 'keys', globals.Set.prototype.values, true);
              }
  
              // Shim incomplete iterator implementations.
              addIterator(Object.getPrototypeOf((new globals.Map()).keys()));
              addIterator(Object.getPrototypeOf((new globals.Set()).keys()));
  
              if (functionsHaveNames && globals.Set.prototype.has.name !== 'has') {
                  // Microsoft Edge v0.11.10074.0 is missing a name on Set#has
                  var anonymousSetHas = globals.Set.prototype.has;
                  overrideNative(globals.Set.prototype, 'has', function has(key) {
                      return _call(anonymousSetHas, this, key);
                  });
              }
          }
          defineProperties(globals, collectionShims);
          addDefaultSpecies(globals.Map);
          addDefaultSpecies(globals.Set);
      }
  
      var throwUnlessTargetIsObject = function throwUnlessTargetIsObject(target) {
          if (!ES.TypeIsObject(target)) {
              throw new TypeError('target must be an object');
          }
      };
  
      // Some Reflect methods are basically the same as
      // those on the Object global, except that a TypeError is thrown if
      // target isn't an object. As well as returning a boolean indicating
      // the success of the operation.
      var ReflectShims = {
          // Apply method in a functional form.
          apply: function apply() {
              return ES.Call(ES.Call, null, arguments);
          },
  
          // New operator in a functional form.
          construct: function construct(constructor, args) {
              if (!ES.IsConstructor(constructor)) {
                  throw new TypeError('First argument must be a constructor.');
              }
              var newTarget = arguments.length > 2 ? arguments[2] : constructor;
              if (!ES.IsConstructor(newTarget)) {
                  throw new TypeError('new.target must be a constructor.');
              }
              return ES.Construct(constructor, args, newTarget, 'internal');
          },
  
          // When deleting a non-existent or configurable property,
          // true is returned.
          // When attempting to delete a non-configurable property,
          // it will return false.
          deleteProperty: function deleteProperty(target, key) {
              throwUnlessTargetIsObject(target);
              if (supportsDescriptors) {
                  var desc = Object.getOwnPropertyDescriptor(target, key);
  
                  if (desc && !desc.configurable) {
                      return false;
                  }
              }
  
              // Will return true.
              return delete target[key];
          },
  
          has: function has(target, key) {
              throwUnlessTargetIsObject(target);
              return key in target;
          }
      };
  
      if (Object.getOwnPropertyNames) {
          Object.assign(ReflectShims, {
              // Basically the result of calling the internal [[OwnPropertyKeys]].
              // Concatenating propertyNames and propertySymbols should do the trick.
              // This should continue to work together with a Symbol shim
              // which overrides Object.getOwnPropertyNames and implements
              // Object.getOwnPropertySymbols.
              ownKeys: function ownKeys(target) {
                  throwUnlessTargetIsObject(target);
                  var keys = Object.getOwnPropertyNames(target);
  
                  if (ES.IsCallable(Object.getOwnPropertySymbols)) {
                      _pushApply(keys, Object.getOwnPropertySymbols(target));
                  }
  
                  return keys;
              }
          });
      }
  
      var callAndCatchException = function ConvertExceptionToBoolean(func) {
          return !throwsError(func);
      };
  
      if (Object.preventExtensions) {
          Object.assign(ReflectShims, {
              isExtensible: function isExtensible(target) {
                  throwUnlessTargetIsObject(target);
                  return Object.isExtensible(target);
              },
              preventExtensions: function preventExtensions(target) {
                  throwUnlessTargetIsObject(target);
                  return callAndCatchException(function () {
                      Object.preventExtensions(target);
                  });
              }
          });
      }
  
      if (supportsDescriptors) {
          var internalGet = function get(target, key, receiver) {
              var desc = Object.getOwnPropertyDescriptor(target, key);
  
              if (!desc) {
                  var parent = Object.getPrototypeOf(target);
  
                  if (parent === null) {
                      return void 0;
                  }
  
                  return internalGet(parent, key, receiver);
              }
  
              if ('value' in desc) {
                  return desc.value;
              }
  
              if (desc.get) {
                  return ES.Call(desc.get, receiver);
              }
  
              return void 0;
          };
  
          var internalSet = function set(target, key, value, receiver) {
              var desc = Object.getOwnPropertyDescriptor(target, key);
  
              if (!desc) {
                  var parent = Object.getPrototypeOf(target);
  
                  if (parent !== null) {
                      return internalSet(parent, key, value, receiver);
                  }
  
                  desc = {
                      value: void 0,
                      writable: true,
                      enumerable: true,
                      configurable: true
                  };
              }
  
              if ('value' in desc) {
                  if (!desc.writable) {
                      return false;
                  }
  
                  if (!ES.TypeIsObject(receiver)) {
                      return false;
                  }
  
                  var existingDesc = Object.getOwnPropertyDescriptor(receiver, key);
  
                  if (existingDesc) {
                      return Reflect.defineProperty(receiver, key, {
                          value: value
                      });
                  } else {
                      return Reflect.defineProperty(receiver, key, {
                          value: value,
                          writable: true,
                          enumerable: true,
                          configurable: true
                      });
                  }
              }
  
              if (desc.set) {
                  _call(desc.set, receiver, value);
                  return true;
              }
  
              return false;
          };
  
          Object.assign(ReflectShims, {
              defineProperty: function defineProperty(target, propertyKey, attributes) {
                  throwUnlessTargetIsObject(target);
                  return callAndCatchException(function () {
                      Object.defineProperty(target, propertyKey, attributes);
                  });
              },
  
              getOwnPropertyDescriptor: function getOwnPropertyDescriptor(target, propertyKey) {
                  throwUnlessTargetIsObject(target);
                  return Object.getOwnPropertyDescriptor(target, propertyKey);
              },
  
              // Syntax in a functional form.
              get: function get(target, key) {
                  throwUnlessTargetIsObject(target);
                  var receiver = arguments.length > 2 ? arguments[2] : target;
  
                  return internalGet(target, key, receiver);
              },
  
              set: function set(target, key, value) {
                  throwUnlessTargetIsObject(target);
                  var receiver = arguments.length > 3 ? arguments[3] : target;
  
                  return internalSet(target, key, value, receiver);
              }
          });
      }
  
      if (Object.getPrototypeOf) {
          var objectDotGetPrototypeOf = Object.getPrototypeOf;
          ReflectShims.getPrototypeOf = function getPrototypeOf(target) {
              throwUnlessTargetIsObject(target);
              return objectDotGetPrototypeOf(target);
          };
      }
  
      if (Object.setPrototypeOf && ReflectShims.getPrototypeOf) {
          var willCreateCircularPrototype = function (object, lastProto) {
              var proto = lastProto;
              while (proto) {
                  if (object === proto) {
                      return true;
                  }
                  proto = ReflectShims.getPrototypeOf(proto);
              }
              return false;
          };
  
          Object.assign(ReflectShims, {
              // Sets the prototype of the given object.
              // Returns true on success, otherwise false.
              setPrototypeOf: function setPrototypeOf(object, proto) {
                  throwUnlessTargetIsObject(object);
                  if (proto !== null && !ES.TypeIsObject(proto)) {
                      throw new TypeError('proto must be an object or null');
                  }
  
                  // If they already are the same, we're done.
                  if (proto === Reflect.getPrototypeOf(object)) {
                      return true;
                  }
  
                  // Cannot alter prototype if object not extensible.
                  if (Reflect.isExtensible && !Reflect.isExtensible(object)) {
                      return false;
                  }
  
                  // Ensure that we do not create a circular prototype chain.
                  if (willCreateCircularPrototype(object, proto)) {
                      return false;
                  }
  
                  Object.setPrototypeOf(object, proto);
  
                  return true;
              }
          });
      }
      var defineOrOverrideReflectProperty = function (key, shim) {
          if (!ES.IsCallable(globals.Reflect[key])) {
              defineProperty(globals.Reflect, key, shim);
          } else {
              var acceptsPrimitives = valueOrFalseIfThrows(function () {
                  globals.Reflect[key](1);
                  globals.Reflect[key](NaN);
                  globals.Reflect[key](true);
                  return true;
              });
              if (acceptsPrimitives) {
                  overrideNative(globals.Reflect, key, shim);
              }
          }
      };
      Object.keys(ReflectShims).forEach(function (key) {
          defineOrOverrideReflectProperty(key, ReflectShims[key]);
      });
      var originalReflectGetProto = globals.Reflect.getPrototypeOf;
      if (functionsHaveNames && originalReflectGetProto && originalReflectGetProto.name !== 'getPrototypeOf') {
          overrideNative(globals.Reflect, 'getPrototypeOf', function getPrototypeOf(target) {
              return _call(originalReflectGetProto, globals.Reflect, target);
          });
      }
      if (globals.Reflect.setPrototypeOf) {
          if (valueOrFalseIfThrows(function () {
                  globals.Reflect.setPrototypeOf(1, {});
                  return true;
              })) {
              overrideNative(globals.Reflect, 'setPrototypeOf', ReflectShims.setPrototypeOf);
          }
      }
      if (globals.Reflect.defineProperty) {
          if (!valueOrFalseIfThrows(function () {
                  var basic = !globals.Reflect.defineProperty(1, 'test', { value: 1 });
                  // "extensible" fails on Edge 0.12
                  var extensible = typeof Object.preventExtensions !== 'function' || !globals.Reflect.defineProperty(Object.preventExtensions({}), 'test', {});
                  return basic && extensible;
              })) {
              overrideNative(globals.Reflect, 'defineProperty', ReflectShims.defineProperty);
          }
      }
      if (globals.Reflect.construct) {
          if (!valueOrFalseIfThrows(function () {
                  var F = function F() {};
                  return globals.Reflect.construct(function () {}, [], F) instanceof F;
              })) {
              overrideNative(globals.Reflect, 'construct', ReflectShims.construct);
          }
      }
  
      if (String(new Date(NaN)) !== 'Invalid Date') {
          var dateToString = Date.prototype.toString;
          var shimmedDateToString = function toString() {
              var valueOf = +this;
              if (valueOf !== valueOf) {
                  return 'Invalid Date';
              }
              return ES.Call(dateToString, this);
          };
          overrideNative(Date.prototype, 'toString', shimmedDateToString);
      }
  
      // Annex B HTML methods
      // http://www.ecma-international.org/ecma-262/6.0/#sec-additional-properties-of-the-string.prototype-object
      var stringHTMLshims = {
          anchor: function anchor(name) { return ES.CreateHTML(this, 'a', 'name', name); },
          big: function big() { return ES.CreateHTML(this, 'big', '', ''); },
          blink: function blink() { return ES.CreateHTML(this, 'blink', '', ''); },
          bold: function bold() { return ES.CreateHTML(this, 'b', '', ''); },
          fixed: function fixed() { return ES.CreateHTML(this, 'tt', '', ''); },
          fontcolor: function fontcolor(color) { return ES.CreateHTML(this, 'font', 'color', color); },
          fontsize: function fontsize(size) { return ES.CreateHTML(this, 'font', 'size', size); },
          italics: function italics() { return ES.CreateHTML(this, 'i', '', ''); },
          link: function link(url) { return ES.CreateHTML(this, 'a', 'href', url); },
          small: function small() { return ES.CreateHTML(this, 'small', '', ''); },
          strike: function strike() { return ES.CreateHTML(this, 'strike', '', ''); },
          sub: function sub() { return ES.CreateHTML(this, 'sub', '', ''); },
          sup: function sub() { return ES.CreateHTML(this, 'sup', '', ''); }
      };
      _forEach(Object.keys(stringHTMLshims), function (key) {
          var method = String.prototype[key];
          var shouldOverwrite = false;
          if (ES.IsCallable(method)) {
              var output = _call(method, '', ' " ');
              var quotesCount = _concat([], output.match(/"/g)).length;
              shouldOverwrite = output !== output.toLowerCase() || quotesCount > 2;
          } else {
              shouldOverwrite = true;
          }
          if (shouldOverwrite) {
              overrideNative(String.prototype, key, stringHTMLshims[key]);
          }
      });
  
      var JSONstringifiesSymbols = (function () {
          // Microsoft Edge v0.12 stringifies Symbols incorrectly
          if (!hasSymbols) { return false; } // Symbols are not supported
          var stringify = typeof JSON === 'object' && typeof JSON.stringify === 'function' ? JSON.stringify : null;
          if (!stringify) { return false; } // JSON.stringify is not supported
          if (typeof stringify(Symbol()) !== 'undefined') { return true; } // Symbols should become `undefined`
          if (stringify([Symbol()]) !== '[null]') { return true; } // Symbols in arrays should become `null`
          var obj = { a: Symbol() };
          obj[Symbol()] = true;
          if (stringify(obj) !== '{}') { return true; } // Symbol-valued keys *and* Symbol-valued properties should be omitted
          return false;
      }());
      var JSONstringifyAcceptsObjectSymbol = valueOrFalseIfThrows(function () {
          // Chrome 45 throws on stringifying object symbols
          if (!hasSymbols) { return true; } // Symbols are not supported
          return JSON.stringify(Object(Symbol())) === '{}' && JSON.stringify([Object(Symbol())]) === '[{}]';
      });
      if (JSONstringifiesSymbols || !JSONstringifyAcceptsObjectSymbol) {
          var origStringify = JSON.stringify;
          overrideNative(JSON, 'stringify', function stringify(value) {
              if (typeof value === 'symbol') { return; }
              var replacer;
              if (arguments.length > 1) {
                  replacer = arguments[1];
              }
              var args = [value];
              if (!isArray(replacer)) {
                  var replaceFn = ES.IsCallable(replacer) ? replacer : null;
                  var wrappedReplacer = function (key, val) {
                      var parsedValue = replaceFn ? _call(replaceFn, this, key, val) : val;
                      if (typeof parsedValue !== 'symbol') {
                          if (Type.symbol(parsedValue)) {
                              return assignTo({})(parsedValue);
                          } else {
                              return parsedValue;
                          }
                      }
                  };
                  args.push(wrappedReplacer);
              } else {
                  // create wrapped replacer that handles an array replacer?
                  args.push(replacer);
              }
              if (arguments.length > 2) {
                  args.push(arguments[2]);
              }
              return origStringify.apply(this, args);
          });
      }
  
      return globals;
  }));