anchor.diff:        return size.height;
       return result;
     }
  -  // getDistanceToActualBaseline() must only be called from
  -  // getDistanceToBaseline() and computeDistanceToActualBaseline(). Do
  -  // not call it directly from outside those two methods. It just
  -  // calls computeDistanceToActualBaseline() and caches the result.
  +
  +  /// Calls [computeDistanceToActualBaseline] and caches the result.
  +  ///
  +  /// This function must only be called from [getDistanceToBaseline] and
  +  /// [computeDistanceToActualBaseline]. Do not call this function directly from
  +  /// outside those two methods.
     double getDistanceToActualBaseline(TextBaseline baseline) {
       assert(_debugDoingBaseline);
       _ancestorUsesBaseline = true;
  
positive.code:       child.parentData = new BoxParentData();
    }
  
    // getMinIntrinsicWidth() should return the minimum width that this box could
    // be without failing to render its contents within itself.
    double getMinIntrinsicWidth(BoxConstraints constraints) {
      return constraints.constrainWidth(0.0);
    }
  
    // getMaxIntrinsicWidth() should return the smallest width beyond which
    // increasing the width never decreases the height.
    double getMaxIntrinsicWidth(BoxConstraints constraints) {
      return constraints.constrainWidth(0.0);
    }
  
    // getMinIntrinsicHeight() should return the minimum height that this box could
    // be without failing to render its contents within itself.
    double getMinIntrinsicHeight(BoxConstraints constraints) {
      return constraints.constrainHeight(0.0);
    }
  
    // getMaxIntrinsicHeight should return the smallest height beyond which
    // increasing the height never decreases the width.
    // If the layout algorithm used is width-in-height-out, i.e. the height
    // depends on the width and not vice versa, then this will return the same
    // as getMinIntrinsicHeight().
    double getMaxIntrinsicHeight(BoxConstraints constraints) {
      return constraints.constrainHeight(0.0);
    }
  
negative.code:     return false;
    }
  
    /// Paints each child by walking the child list forwards
    void defaultPaint(PaintingContext context, Offset offset) {
      RenderBox child = firstChild;
      while (child != null) {
  