  assert_equals(
    host.getAnimations({ subtree: true }).length,
    0,
    'Returns no animations with subtree:true when called on the host'
  );
  assert_equals(
    elem.getAnimations({ subtree: true }).length,
    1,
    'Returns one animation when called on a parent in the shadow tree'
  );
}, 'Does NOT cross shadow-tree boundaries when subtree: true is specified');

test(t => {
  const foreignElement
    = document.createElementNS('http://example.org/test', 'test');
  document.body.appendChild(forei