void AddUpdateHandler()
 {
     RemoveUpdateHandler();
     updateHandler     = gameObject.AddComponent <TileUpdateHandler>();
     updateHandler.obj = GetComponent <TileGameObjectEventHandler>();
 }
 void RemoveUpdateHandler()
 {
     updateHandler = null;
     Destroy(gameObject.GetComponent <TileUpdateHandler>());
 }
 void AddUpdateHandler()
 {
     RemoveUpdateHandler();
     updateHandler     = gameObject.AddComponent <TileUpdateHandler>();
     updateHandler.obj = this;
 }