nd(createSource('/media-source/mp4/test.mp4#a', '(min-width: 200px)'));
  v.append(createSource('/media-source/mp4/test.mp4#b'));
  await rAF();
  await rAF();
  window.resolveBeforeEnvChange(hash(v.currentSrc));
  window.frameElement.width = '150';
  await rAF();
  await rAF();
  window.resolveAfterEnvChange(hash(v.currentSrc));
  v.load()
  await rAF();
  await rAF();
  window.resolveAfterLoadCalled(hash(v.currentSrc));
})();
</script>
