checked"));
  mi.checked = true;
  assert_equals(mi.checked, false, "cannot be checked when detached");
  assert_false(mi.matches(":checked"));

  document.body.append(mi);

  assert_equals(mi.checked, false, "defaults to unchecked when connected");
  assert_false(mi.matches(":checked"));
  mi.checked = true;
  assert_equals(mi.checked, false,
      "cannot be checked when not attached in a menulist");
  assert_false(mi.matches(":checked"));

  mi.remove();
}, "menuitem is not checkable on its own");

test(