ach(tag => {
    test((t) => {
      const element = document.createElement(tag);
      element.setAttribute('popover','auto');
      document.body.appendChild(element);
      t.add_cleanup(() => element.remove());
      assertIsFunctionalPopover(element, true);
    }, `A <${tag} popover> element should behave as a popover.`);
    test((t) => {
      const element = document.createElement(tag);
      document.body.appendChild(element);
      t.add_cleanup(() => element.remove());
      assertNotAPopover(ele