<!DOCTYPE html>
<html>
  <script>
    document.expando = 42;
    document.shadowedIframe = 42;
    Object.setPrototypeOf(document, Object.create(HTMLDocument.prototype,
      {
        shadowedIframe: { value: 42 },
        iframe: { value: 42 },
        defaultView: { value: 42 },
        addEventListener: { value: 42 },
        toString: { value: 42 },
      }));
    document.documentElement.expando = 42;
    Object.defineProperty(document.documentElement, "version", { value: 42 });
  </script>
  <iframe name="shadowedIframe" id="shadowedIframe"></iframe>
  <iframe name="iframe" id="iframe"></iframe>
  <iframe name="document" id="document"></iframe>
  <iframe name="self" id="self"></iframe>
  <iframe name="addEventListener" id="addEventListener"></iframe>
  <iframe name="toString" id="toString"></iframe>
  <iframe name="item" id="item"></iframe>
</html>
