@Override
    public void onKeyRelease(KeyEvent e) {
        if (e.getKeyCode() == KeyEvent.VK_UP
                || e.getKeyCode() == KeyEvent.VK_DOWN || e.getKeyCode() == KeyEvent.VK_W || e.getKeyCode() == KeyEvent.VK_S) {
            paddleLeft.stop();
            paddleRight.stop();
        }
    }