sert_true(multiple2.checked, "multiple2 checked [after multiple3 checked]");
  assert_true(multiple2.matches(":checked"),
      "multiple2 IS :checked [after multiple3 checked]");
  assert_true(multiple3.checked, "multiple3 checked [after multiple3 checked]");
  assert_true(multiple3.matches(":checked"),
      "multiple3 IS checked [after multiple3 checked]");
}, "checkable multiple");

test(() => {
  const menulist = document.createElement('menulist');
  const fieldset = menulist.appendChild(document.creat