static JPanel volatileImageSurfaceDemo() {
  new Timings timings;
  JLabel lblTimings = jlabel();
  
  var surface = new JVolatileImageSurface {
    void renderVolatile(int w, int h, Graphics2D g) {
      timings.do("background", -> {
        g.setColor(Color.green);
        g.fillRect(0, 0, w, h);
      }
      timings.do("circle", ->
        fillCircle(g, w/2, h/2, w/4, Color.blue));
    }
  };
  
  awtDoEvery(lblTimings, 1.0, -> lblTimings.setText(timings.toStringSingleLine()));
  ret centerAndSouthWithMargin(surface, lblTimings);
}