static void registerLeftKey(JFrame frame, O r) {
  S name = "Left";
  Action action = abstractAction(name, r);
  JComponent pnl = frame.getRootPane();
  KeyStroke keyStroke = KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0);
  pnl.getActionMap().put(name, action);
  pnl.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(keyStroke, name);
}