svoid setText(JTextComponent c, O text) {
  setText((O) c, text);
}

svoid setText(JLabel c, O text) {
  setText((O) c, text);
}

svoid setText(JButton c, O text) {
  setText((O) c, text);
}

svoid setText(fO c, O text) {
  if (c == null) ret;
  final S s = str(text);
  swingAndWait(r { call(c, "setText", s) });
}