svoid test_imageSurfaceRevalidationInFullCenter() {
  ImageSurface imageSurface = imageSurface();
  imageSurface.setImage(whiteImage(50, 50));
  showFrame(jMinSize(500, 500, jscroll_borderless(setBackground(Color.gray, jFullCenter(imageSurface)))));
  sleepSeconds(1);
  print("Image surface size: " + jGetSize(imageSurface));
  imageSurface.setImage(whiteImage(100, 100));
  sleepSeconds(1);
  print("Image surface size: " + jGetSize(imageSurface));
}