itemListener = createItemListener();
  public void setModel(ButtonModel newModel)  {    if (newModel == model)      return;    if (model != null)      {        model.removeActionListener(actionListener);        model.removeChangeListener(changeListener);        model.removeItemListener(itemListener);      }    ButtonModel old = model;    model = newModel;    if (model != null)      {        model.addActionListener(actionListener);        model.addChangeListener(changeListener);        model.addItemListener(itemListener);      }    firePropertyChange(MODEL_CHANGED_PROPERTY, old, model);    revalidate();    repaint();  }