anchor.diff:        train.imageRenderer.image = imageInfo.image;
       });
     }
  -  // TODO(ianh): interactivity on the rows to toggle the circle icons
  -  new Timer(new Duration(seconds: 1), debugDumpRenderTree);
  -}
  +}
  
positive.code:         backgroundColor: const Color(0xFFFFFFFF)
        ),
        child: new RenderPadding(
          padding: new EdgeInsets.TRBL(
            ui.window.padding.top,
            ui.window.padding.right,
            ui.window.padding.bottom,
            ui.window.padding.left
          ),
          child: new RenderViewport(
            child: new RenderBlock(
              children: <RenderBox>[
                new RenderPadding(
                  padding: new EdgeInsets.TRBL(4.0, 4.0, 8.0, 4.0),
                  child: new RenderParagraph(
                    new TextSpan(
                      text: 'My 2016 Märklin Trains Wishlist',
  
negative.code:     return getMinIntrinsicHeight(constraints);
    }
  
    double _baselineDistance;
    @override
    double computeDistanceToActualBaseline(TextBaseline baseline) {
      // returns the baseline of the first cell that has a baseline in the first row
      assert(!needsLayout);
      return _baselineDistance;
    }
  
    Iterable<RenderBox> column(int x) sync* {
  