code: function (coordinates) {
                  var element = this._candidateForDrag;
                  if (!element) {
                      return;
                  }
  
                  this._activeDrag = element;
                  this._dragStarted = true;
                  element.start(coordinates);
              }
docs: After an activation delay, if no mouseup event is raised the drag has started.
  @param {Object} coordinates X and Y coordinates of the initial mouse position
  @private