
  </fieldset>
  <fieldset checkable=single>
    <menuitem id=single1></menuitem>
    <menuitem id=single2></menuitem>
    <menuitem id=single3></menuitem>
  </fieldset>
  <fieldset checkable=multiple>
    <menuitem id=multiple1></menuitem>
    <menuitem id=multiple2></menuitem>
    <menuitem id=multiple3></menuitem>
  </fieldset>
</menulist>

<script>
test(() => {
  const mi = document.createElement('menuitem');
  assert_false(mi.checked, "defaults to unchecked when detached");
  assert_false(mi.matches(":