static <A extends Component> A centerFrame_oldMethod(A c) {
  Window w = getWindow(c);
  if (w != null)
    w.setLocationRelativeTo(null); // magic trick
  ret c;
}

static <A extends Component> A centerFrame_oldMethod(int w, int h, A c) {
  ret centerFrame_oldMethod(setFrameSize(w, h, c));
}