static JMenuBar addMenuBar(JFrame f) {
  if (f = null) null;
  JMenuBar bar = f.getJMenuBar();
  if (bar == null) {
    f.setJMenuBar(bar = new JMenuBar());
    revalidateFrame(f);
  }
  ret bar;
}

static JMenuBar addMenuBar(Component c) {
  ret addMenuBar(getFrame(c));
}