private class RadioButtonGroup extends UndoableButtonGroup {
@Override
protected UndoableEdit createUndoableEdit(ButtonModel previousSelection, ButtonModel newSelection) {
return new ButtonGroupUndoableEdit(this, previousSelection, newSelection) {
@Override
public void redo() throws CannotRedoException {
super.redo();
actionPerformed(new ActionEvent(this, ActionEvent.ACTION_PERFORMED, "redo"));