code: function WSMux(urlOrWs, options) {
    EventEmitter.call(this);
    this.options = util._extend({mask: true}, options);
    this.closed = false;
    this.channels = {};
    this.pending = [];
    this._openWebsocket(urlOrWs);
  }
docs: Websocket multiplexer
  @param urlOrWs the url to open the webscoket to multiplex
  @param options
  @constructor