code: func DragEnd(xu *xgbutil.XUtil, ev xevent.ButtonReleaseEvent) {
  	if mouseDragEnd(xu) != nil {
  		mouseDragEnd(xu)(xu, int(ev.RootX), int(ev.RootY),
  			int(ev.EventX), int(ev.EventY))
  	}
  
  	dragUngrab(xu)
  	mouseDragStepSet(xu, nil)
  	mouseDragEndSet(xu, nil)
  }
docs: // DragEnd executes the "end" function registered for the current drag.
  // This must be called at some point if DragStart has been called.