<!DOCTYPE html>
<meta charset="utf-8">
<link rel="author" href="mailto:masonf@chromium.org">
<link rel=help href="https://github.com/whatwg/html/pull/10705">
<script src="../../../resources/testharness.js"></script>
<script src="../../../resources/testharnessreport.js"></script>

<script>
  test(() => {
    const doc = document.implementation.createHTMLDocument();
    const popover = doc.createElement('div');
    popover.setAttribute('popover','');
    doc.body.appendChild(popover);
    assert_throws_dom('I