anchor.diff:    static const String VERTICAL_ORIENTATION = "none";
     static const String HORIZONTAL_ORIENTATION = "left";
     final List<ViewNode> _children = new List();
  +  ViewNode _parent;
     String _orientation = VERTICAL_ORIENTATION;
     DataModel _model;
     DivElement _container;
     DivElement _content;
     ParagraphElement _nodeLabel;
  -  final int labelHeight = 19;
  -  final int padding = 3;
  +  final int _labelHeight = 19;
  +  final int _padding = 3;
   
     ViewNode(this._model, num width, num height, [this._orientation]) {
       assert(this._model != null);
  
positive.code:         ..margin = "0px"
          ..padding = "0px"
          ..position = "absolute"
          ..left = "${padding}px"
          ..right = "${padding}px"
          ..bottom = "${padding}px"
          ..top = "${labelHeight + padding}px";
      _container.children.add(_nodeLabel);
      _container.children.add(_content);
    }
    
    void _fixBorders(ViewNode node) {
      int index = this._children.lastIndexOf(node) - 1;
      if (index > -1) {
        ViewNode previousSibling = this._children[index];
        if (!previousSibling.isRoot()) {
          if (previousSibling._orientation == HORIZONTAL_ORIENTATION) {
            node._container.style.borderLeftWidth = "0px";
          } else {
            node._container.style.borderTopWidth = "0px";
          }
        }
      }
    }
  
    void add(ViewNode child) {
      _content.children.add(child._container);
      this._children.add(child);
      _fixBorders(child);
    }
  
negative.code:     _nodeLabel.style..marginAfter = "0px"
          ..marginBefore = "0px";
      _nodeLabel.text = this._model.title;
      _nodeLabel.style.height = "${_labelHeight}";
      if (_model.isLeaf()) {
        _createLeafNode();
      } else {
  