t(async () => {
  const img1 = document.createElement('img');
  container1.appendChild(img1);
  const img1Load = new Promise(resolve => img1.onload = resolve);
  img1.src = 'resources/dice.png';
  await img1Load;
  assert_not_equals(img1.height, 0, 'height');

  const img2 = document.createElement('img');
  container2.appendChild(img2);
  const img2Load = new Promise(resolve => img2.onload = resolve);
  img2.src = 'resources/dice.png';
  await img2Load;
  assert_not_equals(img2.width, 0, 'width');

  const 