anchor.diff:      double childRadius = radius + padding;
       double paddingTheta = math.atan(padding / (radius + outerDeltaRadius));
       double innerTheta = paddingTheta; // increments with each child
  -    double remainingTheta = constraints.maxDeltaTheta - (innerTheta + paddingTheta);
  +    double remainingDeltaTheta = constraints.maxDeltaTheta - (innerTheta + paddingTheta);
       RenderSector child = firstChild;
       while (child != null) {
         SectorConstraints innerConstraints = new SectorConstraints(
           maxDeltaRadius: innerDeltaRadius,
  -        maxDeltaTheta: remainingTheta
  +        maxDeltaTheta: remainingDeltaTheta
         );
         SectorDimensions childDimensions = child.getIntrinsicDimensions(innerConstraints, childRadius);
         innerTheta += childDimensions.deltaTheta;
  -      remainingTheta -= childDimensions.deltaTheta;
  +      remainingDeltaTheta -= childDimensions.deltaTheta;
         assert(child.parentData is SectorChildListParentData);
         child = child.parentData.nextSibling;
         if (child != null) {
           innerTheta += paddingTheta;
  -        remainingTheta -= paddingTheta;
  +        remainingDeltaTheta -= paddingTheta;
         }
       }
       return new SectorDimensions.withConstraints(constraints,
  
positive.code:   }
  
    void setParentData(RenderNode child) {
      if (child.parentData is! SectorChildListParentData)
        child.parentData = new SectorChildListParentData();
    }
  
negative.code:     this.minDeltaRadius: 0.0,
      this.maxDeltaRadius: double.INFINITY,
      this.minDeltaTheta: 0.0,
      this.maxDeltaTheta: kTwoPi
    });
  
    const SectorConstraints.tight({ double deltaRadius: 0.0, double deltaTheta: 0.0 })
      : minDeltaRadius = deltaRadius,
  