ript>

<script id=childNodesLength>
  testing.expectEqual(1, link.childNodes.length);
  testing.expectEqual(0, text.childNodes.length);
</script>

<script id=insertBefore>
  let insertBefore = document.createElement('a');
  testing.expectEqual(true, link.insertBefore(insertBefore, text) !== undefined);
  testing.expectEqual('a', link.firstChild.localName);

  let insertBefore2 = document.createElement('b');
  testing.expectEqual('b', link.insertBefore(insertBefore2, null).localName);
  testing.expectEqual('