tiveTree.previousElementSibling(d2), d1);
    });

    test('fragment element accessors', function() {
      // IE/Edge does not have element accessors on DocumentFragment.
      if (navigator.userAgent.match(/Trident|Edge/)) {
        this.skip();
      }
      let el = document.createDocumentFragment();
      let d1 = document.createElement('div');
      let d2 = document.createElement('div');
      el.appendChild(d1);
      el.appendChild(d2);
      assert.equal(ShadyDOM.nativeTree.firstElementChild(el),