public void RemoveUpdateCallBack(IUpdateSortingOrder remove)
 {
     if (_updateCallBack.Contains(remove))
     {
         _updateCallBack.Remove(remove);
     }
 }
 public void AddUpdateCallBack(IUpdateSortingOrder add)
 {
     if (!_updateCallBack.Contains(add))
     {
         _updateCallBack.Add(add);
     }
 }