code: function onMouseWheel( tracker, event ) {
          event = $.getEvent( event );
  
          // Simulate a 'wheel' event
          var simulatedEvent = {
              target:     event.target || event.srcElement,
              type:       "wheel",
              shiftKey:   event.shiftKey || false,
              clientX:    event.clientX,
              clientY:    event.clientY,
              pageX:      event.pageX ? event.pageX : event.clientX,
              pageY:      event.pageY ? event.pageY : event.clientY,
              deltaMode:  event.type == "MozMousePixelScroll" ? 0 : 1, // 0=pixel, 1=line, 2=page
              deltaX:     0,
              deltaZ:     0
          };
  
          // Calculate deltaY
          if ( $.MouseTracker.wheelEventName == "mousewheel" ) {
              simulatedEvent.deltaY = -event.wheelDelta / $.DEFAULT_SETTINGS.pixelsPerWheelLine;
          } else {
              simulatedEvent.deltaY = event.detail;
          }
  
          handleWheelEvent( tracker, simulatedEvent, event );
      }
docs: Handler for 'mousewheel', 'DOMMouseScroll', and 'MozMousePixelScroll' events
  
  @private
  @inner