lib/host.js
function HostMap() {
  events.EventEmitter.call(this);
  this._items = {};
  this._values = null;
  Object.defineProperty(this, 'length', { get: function () { return this.values().length; }, enumerable: true });
}
function HostMap() {
  events.EventEmitter.call(this);
  this._items = {};
  this._values = null;
  Object.defineProperty(this, 'length', { get: function () { return this.values().length; }, enumerable: true });
}
Represents an associative-array of {@link Host hosts} that can be iterated.
It creates an internal copy when adding or removing, making it safe to iterate using the values() method within async operations.
@extends events.EventEmitter
@constructor