anchor.diff:  
       var cssElement = document.head.query('#${_CSSID}');
       if (cssElement == null){
  -      document.head.elements.add(new Element.html(
  +      document.head.children.add(new Element.html(
             '<style id="${_CSSID}"></style>'));
         cssElement = document.head.query('#${_CSSID}');
       }
  
positive.code:   final bool _isLayoutTest;
    HtmlEnhancedConfiguration(this._isLayoutTest);
  
    // TODO(rnystrom): Get rid of this if we get canonical closures for methods.
    EventListener _onErrorClosure;
    EventListener _onMessageClosure;
  
    void _installHandlers() {
      if (_onErrorClosure == null) {
        _onErrorClosure =
            (e) => handleExternalError(e, '(DOM callback has errors)');
        // Listen for uncaught errors.
        window.on.error.add(_onErrorClosure);
      }
      if (_onMessageClosure == null) {
        _onMessageClosure = (e) => processMessage(e);
        // Listen for errors from JS.
        window.on.message.add(_onMessageClosure);
      }
    }
  
    void _uninstallHandlers() {
      if (_onErrorClosure != null) {
        window.on.error.remove(_onErrorClosure);
        _onErrorClosure = null;
      }
      if (_onMessageClosure != null) {
        window.on.message.remove(_onMessageClosure);
        _onMessageClosure = null;
      }
    }
  
  
negative.code:     }
  
      addRowElement(id, status, description){
        te.children.add(
          new Element.html(
            ''' <div>
                  <div class='$display unittest-row-${groupID} $background'>
  