est(t => {
  const control = document.createElement('my-control');
  document.body.appendChild(control);
  t.add_cleanup(() => control.remove());
  const flags = {valueMissing: true};
  const m = 'non-empty message';

  // Self
  control.i.setValidity(flags, m, control);
}, '"anchor" argument of setValidity(): passing self');

test(() => {
  const element = new NotFormAssociatedElement();
  assert_throws_dom('NotSupportedError', () => element.i.checkValidity());
}, "checkValidity() should throw NotSupported