private static void OnQuickIKManagerAdded(QuickIKManagerExecuteInEditMode ikManager)
 {
     if (!_ikManagers.Contains(ikManager))
     {
         _ikManagers.Add(ikManager);
     }
 }
 private static void OnQuickIKManagerRemoved(QuickIKManagerExecuteInEditMode ikManager)
 {
     _ikManagers.Remove(ikManager);
 }