static JRadioButton jradiobutton(S text, ButtonGroup group) {
  ret swing(func -> JRadioButton {
    JRadioButton rb = new JRadioButton(text);
    if (group != null) group.add(rb);
    ret rb;
  });
}

static JRadioButton jradiobutton(ButtonGroup group, S text) {
  ret jradiobutton(text, group);
}