docs: function (gesture, id) {
                  if (this._idList[gesture]) {
                      var element = this._idList[gesture][id];
                      if (gesture == "drag" && element && element == this._activeDrag) {
                          // the element being dragged has been disposed,
                          // terminate the drag:
                          this._dragStartPosition = null;
                          disconnectMouseEvents(this);
                          this._candidateForDrag = null;
                          this._activeDrag = null;
                      }
                      delete this._idList[gesture][id];
                  }
              }