docs: function (cb) {
              if (!this._robot) {
                  this._robot = Aria.$frameworkWindow.top.SeleniumJavaRobot;
                  this._robot.getOffset({
                      fn : this._offsetReceived,
                      scope : this
                  });
              }
              if (cb) {
                  if (this._robotInitialized) {
                      this.$callback(cb);
                  } else {
                      this.$onOnce({
                          "robotInitialized" : cb
                      });
                  }
              }
          }