@Override
    public void propertyChange(PropertyChangeEvent event) {
      Object oldValue = event.getOldValue();
      if (oldValue instanceof TreeModel) ((TreeModel)oldValue).removeTreeModelListener(myTreeModelListener);
      Object newValue = event.getNewValue();
      if (newValue instanceof TreeModel) ((TreeModel)newValue).addTreeModelListener(myTreeModelListener);
    }
@Override
    public void propertyChange(PropertyChangeEvent event)