code: function (event, extraData) {
              if (!this.__validateNbTouches(event)) {
                  return null;
              }
              this.currentData = {
                  positions : ariaTouchEvent.getPositions(event),
                  time : (new Date()).getTime()
              };
              if (this._getFakeEventsMap().move) {
                  return this._raiseFakeEvent(event, this._getFakeEventsMap().move, extraData);
              } else {
                  return (event.returnValue != null) ? event.returnValue : !event.defaultPrevented;
              }
          }
docs: Generic optional move: manages intermediate states during the gesture
  @param {Object} event the original event
  @protected
  @return {Boolean} false if preventDefault is true