anchor.diff:  }
   
   /*
  - * SkyNodeWrappers correspond to a desired state of a RenderCSS. They are fully
  - * immutable, with one exception: A UINode which is a Component which lives within
  - * an SkyElementWrapper's children list, may be replaced with the "old" instance if it
  - * has become stateful.
  + * RenderNodeWrappers correspond to a desired state of a RenderCSS.
  + * They are fully immutable, with one exception: A UINode which is a
  + * Component which lives within an OneChildListRenderNodeWrapper's
  + * children list, may be replaced with the "old" instance if it has
  + * become stateful.
    */
  -abstract class SkyNodeWrapper extends UINode {
  -
  -  static final Map<RenderCSS, SkyNodeWrapper> _nodeMap =
  -      new HashMap<RenderCSS, SkyNodeWrapper>();
  -
  -  static SkyNodeWrapper _getMounted(RenderCSS node) => _nodeMap[node];
  -
  -  SkyNodeWrapper({ Object key }) : super(key: key);
  -
  -  SkyNodeWrapper get _emptyNode;
  +abstract class RenderNodeWrapper extends UINode {
  +
  +  static final Map<RenderCSS, RenderNodeWrapper> _nodeMap =
  +      new HashMap<RenderCSS, RenderNodeWrapper>();
  +
  +  static RenderNodeWrapper _getMounted(RenderCSS node) => _nodeMap[node];
  +
  +  RenderNodeWrapper({ Object key }) : super(key: key);
  +
  +  RenderNodeWrapper get _emptyNode;
   
     RenderCSS _createNode();
   
  
positive.code: 
  final List<UINode> _emptyList = new List<UINode>();
  
  abstract class SkyElementWrapper extends SkyNodeWrapper {
  
    final List<UINode> children;
    final Style style;
    final String inlineStyle;
  
    SkyElementWrapper({
      Object key,
      List<UINode> children,
      this.style,
  
negative.code:   }
  }
  
  class Image extends OneChildListRenderNodeWrapper {
  
    RenderCSSImage _root;
    RenderCSSImage _createNode() => new RenderCSSImage(this, this.src, this.width, this.height);
  
    static final Image _emptyImage = new Image();
  
    RenderNodeWrapper get _emptyNode => _emptyImage;
  
    final String src;
    final int width;
  