DOM.flush();
    });

    teardown(function() {
      el.parentNode.removeChild(el);
    });

    test('node accessors', function() {
      let srFirst = el.shadowRoot.firstChild;
      let srLast = el.shadowRoot.lastChild;
      let content = el.firstChild;
      assert.equal(ShadyDOM.nativeTree.firstChild(el), srFirst);
      assert.equal(ShadyDOM.nativeTree.lastChild(el), srLast);
      assert.equal(ShadyDOM.nativeTree.parentNode(srFirst), el);
      assert.equal(ShadyDOM.nativeTree.nextSibling(srFirst),