sertBefore', function() {
      let d = document.createElement('div');
      let srFirst = el.shadowRoot.firstChild;
      ShadyDOM.nativeMethods.insertBefore.call(el, d, srFirst);
      assert.equal(ShadyDOM.nativeTree.firstChild(el), d);
    });

    test('removeChild', function() {
      let srFirst = el.shadowRoot.firstChild;
      let srLast = el.shadowRoot.lastChild;
      let content = el.firstChild;
      ShadyDOM.nativeMethods.removeChild.call(el, srFirst);
      ShadyDOM.nativeMethods.removeChild.