anchor.diff:      RenderSector child = firstChild;
       while (child != null) {
         assert(child.parentData is SectorChildListParentData);
  -      canvas.paintChild(child, new sky.Point(0.0, 0.0));
  +      canvas.paintChild(child, new Point(0.0, 0.0));
         child = child.parentData.nextSibling;
       }
     }
  
positive.code:     RenderSector child = firstChild;
      while (child != null) {
        assert(child.parentData is SectorChildListParentData);
        canvas.paintChild(child, new sky.Point(0.0, 0.0));
        child = child.parentData.nextSibling;
      }
    }
  
negative.code:   void paint(RenderObjectDisplayList canvas) {
      super.paint(canvas);
      if (child != null) {
        Rect bounds = new Rect.fromSize(size);
        canvas.paintChild(child, bounds.center);
      }
    }
  
    bool hitTest(HitTestResult result, { Point position }) {
      double x = position.x;
      double y = position.y;
      if (child == null)
  