TreeViewItem.HandleGUIEvents C# (CSharp) Method

    void HandleGUIEvents()
    {
        // Handle events
        Event evt = Event.current;
        EventType currentEventType = evt.type;

        if (currentEventType == EventType.MouseDrag)
        {
            if (null != Dragged)
            {
                try{
                DragAndDrop.PrepareStartDrag();
                Dragged.Invoke(ParentControl.SelectedItem, new DragEventArgs());
                evt.Use();
                }
                catch (Exception e) {
                    Debug.Log (e);
                }
            }
        }
    }