public void SelectionUpdate()
 {
     foreach (TreeViewItem item in TreeViewExtension.GetExpandedTreeViewItems(treeView))
     {
         object tag = (item as DragDropTreeViewItem).Tag;
         if (tag is GameObject)
         {
             if (!EditorHandler.SelectedGameObjects.Contains((tag as GameObject)))
             {
                 TreeViewExtension.SetIsSelected(item, false);
             }
             else
             {
                 TreeViewExtension.SetIsSelected(item, true);
             }
         }
     }
 }