code: function Request(opts) {
      opts = opts || {};
      this.id = opts.id || generateRequestId();
      this.data = opts.data;
      this.startTs = Date.now();
      this.defer = new Promise.defer();
  }
docs: Construct a new Request.
  @constructor
  @param {Object} opts Options for this request.
  @param {string=} opts.id Optional ID to set on this request. One will be
  generated if this is not provided.
  @param {*=} opts.data Optional data to associate with this request.