static JButton setButtonImage(ImageIcon img, JButton btn) {
  btn.setIcon(img);
  ret btn;
}

static JButton setButtonImage(Image img, JButton btn) {
  btn.setIcon(imageIcon(img));
  ret btn;
}

static JButton setButtonImage(JButton btn, Image img) {
  ret setButtonImage(img, btn);
}

static JButton setButtonImage(JButton btn, ImageIcon img) {
  ret setButtonImage(img, btn);
}