anchor.diff:        child.parentData.theta = 0.0;
         child.layout(new SectorConstraints(maxDeltaRadius: maxChildDeltaRadius), parentUsesSize: true);
         double dimension = (innerRadius + child.deltaRadius) * 2.0;
  -      size = constraints.constrain(new sky.Size(dimension, dimension));
  +      size = constraints.constrain(new Size(dimension, dimension));
       }
     }
   
  
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:       child.parentData = new SectorParentData();
    }
  
    Size getIntrinsicDimensions(BoxConstraints constraints) {
      if (child == null)
        return constraints.constrain(Size.zero);
      assert(child is RenderSector);
      assert(child.parentData is SectorParentData);
      assert(!constraints.isInfinite);
      double maxChildDeltaRadius = math.min(constraints.maxWidth, constraints.maxHeight) / 2.0 - innerRadius;
      SectorDimensions childDimensions = child.getIntrinsicDimensions(new SectorConstraints(maxDeltaRadius: maxChildDeltaRadius), innerRadius);
      double dimension = (innerRadius + childDimensions.deltaRadius) * 2.0;
      return constraints.constrain(new Size(dimension, dimension));
    }
  
    void performLayout() {
      if (child == null) {
        size = constraints.constrain(Size.zero);
      } else {
        assert(child is RenderSector);
        assert(!constraints.isInfinite);
  