text: (function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.BaseBlockTracker = f()}})(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
  const extend = require('xtend')
  const createRandomId = require('json-rpc-random-id')()
  
  module.exports = EthQuery
  
  
  function EthQuery(provider){
    const self = this
    self.currentProvider = provider
  }
  
  //
  // base queries
  //
  
  // default block
  EthQuery.prototype.getBalance =                          generateFnWithDefaultBlockFor(2, 'eth_getBalance')
  EthQuery.prototype.getCode =                             generateFnWithDefaultBlockFor(2, 'eth_getCode')
  EthQuery.prototype.getTransactionCount =                 generateFnWithDefaultBlockFor(2, 'eth_getTransactionCount')
  EthQuery.prototype.getStorageAt =                        generateFnWithDefaultBlockFor(3, 'eth_getStorageAt')
  EthQuery.prototype.call =                                generateFnWithDefaultBlockFor(2, 'eth_call')
  // standard
  EthQuery.prototype.protocolVersion =                     generateFnFor('eth_protocolVersion')
  EthQuery.prototype.syncing =                             generateFnFor('eth_syncing')
  EthQuery.prototype.coinbase =                            generateFnFor('eth_coinbase')
  EthQuery.prototype.mining =                              generateFnFor('eth_mining')
  EthQuery.prototype.hashrate =                            generateFnFor('eth_hashrate')
  EthQuery.prototype.gasPrice =                            generateFnFor('eth_gasPrice')
  EthQuery.prototype.accounts =                            generateFnFor('eth_accounts')
  EthQuery.prototype.blockNumber =                         generateFnFor('eth_blockNumber')
  EthQuery.prototype.getBlockTransactionCountByHash =      generateFnFor('eth_getBlockTransactionCountByHash')
  EthQuery.prototype.getBlockTransactionCountByNumber =    generateFnFor('eth_getBlockTransactionCountByNumber')
  EthQuery.prototype.getUncleCountByBlockHash =            generateFnFor('eth_getUncleCountByBlockHash')
  EthQuery.prototype.getUncleCountByBlockNumber =          generateFnFor('eth_getUncleCountByBlockNumber')
  EthQuery.prototype.sign =                                generateFnFor('eth_sign')
  EthQuery.prototype.sendTransaction =                     generateFnFor('eth_sendTransaction')
  EthQuery.prototype.sendRawTransaction =                  generateFnFor('eth_sendRawTransaction')
  EthQuery.prototype.estimateGas =                         generateFnFor('eth_estimateGas')
  EthQuery.prototype.getBlockByHash =                      generateFnFor('eth_getBlockByHash')
  EthQuery.prototype.getBlockByNumber =                    generateFnFor('eth_getBlockByNumber')
  EthQuery.prototype.getTransactionByHash =                generateFnFor('eth_getTransactionByHash')
  EthQuery.prototype.getTransactionByBlockHashAndIndex =   generateFnFor('eth_getTransactionByBlockHashAndIndex')
  EthQuery.prototype.getTransactionByBlockNumberAndIndex = generateFnFor('eth_getTransactionByBlockNumberAndIndex')
  EthQuery.prototype.getTransactionReceipt =               generateFnFor('eth_getTransactionReceipt')
  EthQuery.prototype.getUncleByBlockHashAndIndex =         generateFnFor('eth_getUncleByBlockHashAndIndex')
  EthQuery.prototype.getUncleByBlockNumberAndIndex =       generateFnFor('eth_getUncleByBlockNumberAndIndex')
  EthQuery.prototype.getCompilers =                        generateFnFor('eth_getCompilers')
  EthQuery.prototype.compileLLL =                          generateFnFor('eth_compileLLL')
  EthQuery.prototype.compileSolidity =                     generateFnFor('eth_compileSolidity')
  EthQuery.prototype.compileSerpent =                      generateFnFor('eth_compileSerpent')
  EthQuery.prototype.newFilter =                           generateFnFor('eth_newFilter')
  EthQuery.prototype.newBlockFilter =                      generateFnFor('eth_newBlockFilter')
  EthQuery.prototype.newPendingTransactionFilter =         generateFnFor('eth_newPendingTransactionFilter')
  EthQuery.prototype.uninstallFilter =                     generateFnFor('eth_uninstallFilter')
  EthQuery.prototype.getFilterChanges =                    generateFnFor('eth_getFilterChanges')
  EthQuery.prototype.getFilterLogs =                       generateFnFor('eth_getFilterLogs')
  EthQuery.prototype.getLogs =                             generateFnFor('eth_getLogs')
  EthQuery.prototype.getWork =                             generateFnFor('eth_getWork')
  EthQuery.prototype.submitWork =                          generateFnFor('eth_submitWork')
  EthQuery.prototype.submitHashrate =                      generateFnFor('eth_submitHashrate')
  
  // network level
  
  EthQuery.prototype.sendAsync = function(opts, cb){
    const self = this
    self.currentProvider.sendAsync(createPayload(opts), function(err, response){
      if (!err && response.error) err = new Error('EthQuery - RPC Error - '+response.error.message)
      if (err) return cb(err)
      cb(null, response.result)
    })
  }
  
  // util
  
  function generateFnFor(methodName){
    return function(){
      const self = this
      var args = [].slice.call(arguments)
      var cb = args.pop()
      self.sendAsync({
        method: methodName,
        params: args,
      }, cb)
    }
  }
  
  function generateFnWithDefaultBlockFor(argCount, methodName){
    return function(){
      const self = this
      var args = [].slice.call(arguments)
      var cb = args.pop()
      // set optional default block param
      if (args.length < argCount) args.push('latest')
      self.sendAsync({
        method: methodName,
        params: args,
      }, cb)
    }
  }
  
  function createPayload(data){
    return extend({
      // defaults
      id: createRandomId(),
      jsonrpc: '2.0',
      params: [],
      // user-specified
    }, data)
  }
  
  },{"json-rpc-random-id":3,"xtend":5}],2:[function(require,module,exports){
  // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  
  function EventEmitter() {
    this._events = this._events || {};
    this._maxListeners = this._maxListeners || undefined;
  }
  module.exports = EventEmitter;
  
  // Backwards-compat with node 0.10.x
  EventEmitter.EventEmitter = EventEmitter;
  
  EventEmitter.prototype._events = undefined;
  EventEmitter.prototype._maxListeners = undefined;
  
  // By default EventEmitters will print a warning if more than 10 listeners are
  // added to it. This is a useful default which helps finding memory leaks.
  EventEmitter.defaultMaxListeners = 10;
  
  // Obviously not all Emitters should be limited to 10. This function allows
  // that to be increased. Set to zero for unlimited.
  EventEmitter.prototype.setMaxListeners = function(n) {
    if (!isNumber(n) || n < 0 || isNaN(n))
      throw TypeError('n must be a positive number');
    this._maxListeners = n;
    return this;
  };
  
  EventEmitter.prototype.emit = function(type) {
    var er, handler, len, args, i, listeners;
  
    if (!this._events)
      this._events = {};
  
    // If there is no 'error' event listener then throw.
    if (type === 'error') {
      if (!this._events.error ||
          (isObject(this._events.error) && !this._events.error.length)) {
        er = arguments[1];
        if (er instanceof Error) {
          throw er; // Unhandled 'error' event
        } else {
          // At least give some kind of context to the user
          var err = new Error('Uncaught, unspecified "error" event. (' + er + ')');
          err.context = er;
          throw err;
        }
      }
    }
  
    handler = this._events[type];
  
    if (isUndefined(handler))
      return false;
  
    if (isFunction(handler)) {
      switch (arguments.length) {
        // fast cases
        case 1:
          handler.call(this);
          break;
        case 2:
          handler.call(this, arguments[1]);
          break;
        case 3:
          handler.call(this, arguments[1], arguments[2]);
          break;
        // slower
        default:
          args = Array.prototype.slice.call(arguments, 1);
          handler.apply(this, args);
      }
    } else if (isObject(handler)) {
      args = Array.prototype.slice.call(arguments, 1);
      listeners = handler.slice();
      len = listeners.length;
      for (i = 0; i < len; i++)
        listeners[i].apply(this, args);
    }
  
    return true;
  };
  
  EventEmitter.prototype.addListener = function(type, listener) {
    var m;
  
    if (!isFunction(listener))
      throw TypeError('listener must be a function');
  
    if (!this._events)
      this._events = {};
  
    // To avoid recursion in the case that type === "newListener"! Before
    // adding it to the listeners, first emit "newListener".
    if (this._events.newListener)
      this.emit('newListener', type,
                isFunction(listener.listener) ?
                listener.listener : listener);
  
    if (!this._events[type])
      // Optimize the case of one listener. Don't need the extra array object.
      this._events[type] = listener;
    else if (isObject(this._events[type]))
      // If we've already got an array, just append.
      this._events[type].push(listener);
    else
      // Adding the second element, need to change to array.
      this._events[type] = [this._events[type], listener];
  
    // Check for listener leak
    if (isObject(this._events[type]) && !this._events[type].warned) {
      if (!isUndefined(this._maxListeners)) {
        m = this._maxListeners;
      } else {
        m = EventEmitter.defaultMaxListeners;
      }
  
      if (m && m > 0 && this._events[type].length > m) {
        this._events[type].warned = true;
        console.error('(node) warning: possible EventEmitter memory ' +
                      'leak detected. %d listeners added. ' +
                      'Use emitter.setMaxListeners() to increase limit.',
                      this._events[type].length);
        if (typeof console.trace === 'function') {
          // not supported in IE 10
          console.trace();
        }
      }
    }
  
    return this;
  };
  
  EventEmitter.prototype.on = EventEmitter.prototype.addListener;
  
  EventEmitter.prototype.once = function(type, listener) {
    if (!isFunction(listener))
      throw TypeError('listener must be a function');
  
    var fired = false;
  
    function g() {
      this.removeListener(type, g);
  
      if (!fired) {
        fired = true;
        listener.apply(this, arguments);
      }
    }
  
    g.listener = listener;
    this.on(type, g);
  
    return this;
  };
  
  // emits a 'removeListener' event iff the listener was removed
  EventEmitter.prototype.removeListener = function(type, listener) {
    var list, position, length, i;
  
    if (!isFunction(listener))
      throw TypeError('listener must be a function');
  
    if (!this._events || !this._events[type])
      return this;
  
    list = this._events[type];
    length = list.length;
    position = -1;
  
    if (list === listener ||
        (isFunction(list.listener) && list.listener === listener)) {
      delete this._events[type];
      if (this._events.removeListener)
        this.emit('removeListener', type, listener);
  
    } else if (isObject(list)) {
      for (i = length; i-- > 0;) {
        if (list[i] === listener ||
            (list[i].listener && list[i].listener === listener)) {
          position = i;
          break;
        }
      }
  
      if (position < 0)
        return this;
  
      if (list.length === 1) {
        list.length = 0;
        delete this._events[type];
      } else {
        list.splice(position, 1);
      }
  
      if (this._events.removeListener)
        this.emit('removeListener', type, listener);
    }
  
    return this;
  };
  
  EventEmitter.prototype.removeAllListeners = function(type) {
    var key, listeners;
  
    if (!this._events)
      return this;
  
    // not listening for removeListener, no need to emit
    if (!this._events.removeListener) {
      if (arguments.length === 0)
        this._events = {};
      else if (this._events[type])
        delete this._events[type];
      return this;
    }
  
    // emit removeListener for all listeners on all events
    if (arguments.length === 0) {
      for (key in this._events) {
        if (key === 'removeListener') continue;
        this.removeAllListeners(key);
      }
      this.removeAllListeners('removeListener');
      this._events = {};
      return this;
    }
  
    listeners = this._events[type];
  
    if (isFunction(listeners)) {
      this.removeListener(type, listeners);
    } else if (listeners) {
      // LIFO order
      while (listeners.length)
        this.removeListener(type, listeners[listeners.length - 1]);
    }
    delete this._events[type];
  
    return this;
  };
  
  EventEmitter.prototype.listeners = function(type) {
    var ret;
    if (!this._events || !this._events[type])
      ret = [];
    else if (isFunction(this._events[type]))
      ret = [this._events[type]];
    else
      ret = this._events[type].slice();
    return ret;
  };
  
  EventEmitter.prototype.listenerCount = function(type) {
    if (this._events) {
      var evlistener = this._events[type];
  
      if (isFunction(evlistener))
        return 1;
      else if (evlistener)
        return evlistener.length;
    }
    return 0;
  };
  
  EventEmitter.listenerCount = function(emitter, type) {
    return emitter.listenerCount(type);
  };
  
  function isFunction(arg) {
    return typeof arg === 'function';
  }
  
  function isNumber(arg) {
    return typeof arg === 'number';
  }
  
  function isObject(arg) {
    return typeof arg === 'object' && arg !== null;
  }
  
  function isUndefined(arg) {
    return arg === void 0;
  }
  
  },{}],3:[function(require,module,exports){
  module.exports = IdIterator
  
  function IdIterator(opts){
    opts = opts || {}
    var max = opts.max || Number.MAX_SAFE_INTEGER
    var idCounter = typeof opts.start !== 'undefined' ? opts.start : Math.floor(Math.random() * max)
  
    return function createRandomId () {
      idCounter = idCounter % max
      return idCounter++
    }
  
  }
  },{}],4:[function(require,module,exports){
  'use strict';
  
  const processFn = (fn, opts) => function () {
  	const P = opts.promiseModule;
  	const args = new Array(arguments.length);
  
  	for (let i = 0; i < arguments.length; i++) {
  		args[i] = arguments[i];
  	}
  
  	return new P((resolve, reject) => {
  		if (opts.errorFirst) {
  			args.push(function (err, result) {
  				if (opts.multiArgs) {
  					const results = new Array(arguments.length - 1);
  
  					for (let i = 1; i < arguments.length; i++) {
  						results[i - 1] = arguments[i];
  					}
  
  					if (err) {
  						results.unshift(err);
  						reject(results);
  					} else {
  						resolve(results);
  					}
  				} else if (err) {
  					reject(err);
  				} else {
  					resolve(result);
  				}
  			});
  		} else {
  			args.push(function (result) {
  				if (opts.multiArgs) {
  					const results = new Array(arguments.length - 1);
  
  					for (let i = 0; i < arguments.length; i++) {
  						results[i] = arguments[i];
  					}
  
  					resolve(results);
  				} else {
  					resolve(result);
  				}
  			});
  		}
  
  		fn.apply(this, args);
  	});
  };
  
  module.exports = (obj, opts) => {
  	opts = Object.assign({
  		exclude: [/.+(Sync|Stream)$/],
  		errorFirst: true,
  		promiseModule: Promise
  	}, opts);
  
  	const filter = key => {
  		const match = pattern => typeof pattern === 'string' ? key === pattern : pattern.test(key);
  		return opts.include ? opts.include.some(match) : !opts.exclude.some(match);
  	};
  
  	let ret;
  	if (typeof obj === 'function') {
  		ret = function () {
  			if (opts.excludeMain) {
  				return obj.apply(this, arguments);
  			}
  
  			return processFn(obj, opts).apply(this, arguments);
  		};
  	} else {
  		ret = Object.create(Object.getPrototypeOf(obj));
  	}
  
  	for (const key in obj) { // eslint-disable-line guard-for-in
  		const x = obj[key];
  		ret[key] = typeof x === 'function' && filter(key) ? processFn(x, opts) : x;
  	}
  
  	return ret;
  };
  
  },{}],5:[function(require,module,exports){
  module.exports = extend
  
  var hasOwnProperty = Object.prototype.hasOwnProperty;
  
  function extend() {
      var target = {}
  
      for (var i = 0; i < arguments.length; i++) {
          var source = arguments[i]
  
          for (var key in source) {
              if (hasOwnProperty.call(source, key)) {
                  target[key] = source[key]
              }
          }
      }
  
      return target
  }
  
  },{}],6:[function(require,module,exports){
  'use strict';
  
  var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();
  
  var _get = function get(object, property, receiver) { if (object === null) object = Function.prototype; var desc = Object.getOwnPropertyDescriptor(object, property); if (desc === undefined) { var parent = Object.getPrototypeOf(object); if (parent === null) { return undefined; } else { return get(parent, property, receiver); } } else if ("value" in desc) { return desc.value; } else { var getter = desc.get; if (getter === undefined) { return undefined; } return getter.call(receiver); } };
  
  function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
  
  function _possibleConstructorReturn(self, call) { if (!self) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return call && (typeof call === "object" || typeof call === "function") ? call : self; }
  
  function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function, not " + typeof superClass); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass; }
  
  var EthQuery = require('eth-query');
  var EventEmitter = require('events');
  var pify = require('pify');
  
  var sec = 1000;
  
  var calculateSum = function calculateSum(accumulator, currentValue) {
    return accumulator + currentValue;
  };
  var blockTrackerEvents = ['sync', 'latest'];
  
  var BaseBlockTracker = function (_EventEmitter) {
    _inherits(BaseBlockTracker, _EventEmitter);
  
    //
    // public
    //
  
    function BaseBlockTracker() {
      var opts = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};
  
      _classCallCheck(this, BaseBlockTracker);
  
      // config
      var _this = _possibleConstructorReturn(this, (BaseBlockTracker.__proto__ || Object.getPrototypeOf(BaseBlockTracker)).call(this));
  
      _this._blockResetDuration = opts.blockResetDuration || 20 * sec;
      // state
      _this._blockResetTimeout;
      _this._currentBlock = null;
      _this._isRunning = false;
      // bind functions for internal use
      _this._onNewListener = _this._onNewListener.bind(_this);
      _this._onRemoveListener = _this._onRemoveListener.bind(_this);
      _this._resetCurrentBlock = _this._resetCurrentBlock.bind(_this);
      // listen for handler changes
      _this._setupInternalEvents();
      return _this;
    }
  
    _createClass(BaseBlockTracker, [{
      key: 'isRunning',
      value: function isRunning() {
        return this._isRunning;
      }
    }, {
      key: 'getCurrentBlock',
      value: function getCurrentBlock() {
        return this._currentBlock;
      }
    }, {
      key: 'getLatestBlock',
      value: async function getLatestBlock() {
        var _this2 = this;
  
        // return if available
        if (this._currentBlock) return this._currentBlock;
        // wait for a new latest block
        var latestBlock = await new Promise(function (resolve) {
          return _this2.once('latest', resolve);
        });
        // return newly set current block
        return latestBlock;
      }
  
      // dont allow module consumer to remove our internal event listeners
  
    }, {
      key: 'removeAllListeners',
      value: function removeAllListeners(eventName) {
        // perform default behavior, preserve fn arity
        if (eventName) {
          _get(BaseBlockTracker.prototype.__proto__ || Object.getPrototypeOf(BaseBlockTracker.prototype), 'removeAllListeners', this).call(this, eventName);
        } else {
          _get(BaseBlockTracker.prototype.__proto__ || Object.getPrototypeOf(BaseBlockTracker.prototype), 'removeAllListeners', this).call(this);
        }
        // re-add internal events
        this._setupInternalEvents();
        // trigger stop check just in case
        this._onRemoveListener();
      }
  
      //
      // to be implemented in subclass
      //
  
    }, {
      key: '_start',
      value: function _start() {
        // default behavior is noop
      }
    }, {
      key: '_end',
      value: function _end() {}
      // default behavior is noop
  
  
      //
      // private
      //
  
    }, {
      key: '_setupInternalEvents',
      value: function _setupInternalEvents() {
        // first remove listeners for idempotence
        this.removeListener('newListener', this._onNewListener);
        this.removeListener('removeListener', this._onRemoveListener);
        // then add them
        this.on('newListener', this._onNewListener);
        this.on('removeListener', this._onRemoveListener);
      }
    }, {
      key: '_onNewListener',
      value: function _onNewListener(eventName, handler) {
        // `newListener` is called *before* the listener is added
        if (!blockTrackerEvents.includes(eventName)) return;
        this._maybeStart();
      }
    }, {
      key: '_onRemoveListener',
      value: function _onRemoveListener(eventName, handler) {
        // `removeListener` is called *after* the listener is removed
        if (this._getBlockTrackerEventCount() > 0) return;
        this._maybeEnd();
      }
    }, {
      key: '_maybeStart',
      value: function _maybeStart() {
        if (this._isRunning) return;
        this._isRunning = true;
        // cancel setting latest block to stale
        this._cancelBlockResetTimeout();
        this._start();
      }
    }, {
      key: '_maybeEnd',
      value: function _maybeEnd() {
        if (!this._isRunning) return;
        this._isRunning = false;
        this._setupBlockResetTimeout();
        this._end();
      }
    }, {
      key: '_getBlockTrackerEventCount',
      value: function _getBlockTrackerEventCount() {
        var _this3 = this;
  
        return blockTrackerEvents.map(function (eventName) {
          return _this3.listenerCount(eventName);
        }).reduce(calculateSum);
      }
    }, {
      key: '_newPotentialLatest',
      value: function _newPotentialLatest(newBlock) {
        var currentBlock = this._currentBlock;
        if (currentBlock && newBlock.hash === currentBlock.hash) return;
        this._setCurrentBlock(newBlock);
      }
    }, {
      key: '_setCurrentBlock',
      value: function _setCurrentBlock(newBlock) {
        var oldBlock = this._currentBlock;
        this._currentBlock = newBlock;
        this.emit('latest', newBlock);
        this.emit('sync', { oldBlock: oldBlock, newBlock: newBlock });
      }
    }, {
      key: '_setupBlockResetTimeout',
      value: function _setupBlockResetTimeout() {
        // clear any existing timeout
        this._cancelBlockResetTimeout();
        // clear latest block when stale
        this._blockResetTimeout = setTimeout(this._resetCurrentBlock, this._blockResetDuration);
        // nodejs - dont hold process open
        if (this._blockResetTimeout.unref) {
          this._blockResetTimeout.unref();
        }
      }
    }, {
      key: '_cancelBlockResetTimeout',
      value: function _cancelBlockResetTimeout() {
        clearTimeout(this._blockResetTimeout);
      }
    }, {
      key: '_resetCurrentBlock',
      value: function _resetCurrentBlock() {
        this._currentBlock = null;
      }
    }]);
  
    return BaseBlockTracker;
  }(EventEmitter);
  
  module.exports = BaseBlockTracker;
  
  },{"eth-query":1,"events":2,"pify":4}]},{},[6])(6)
  });