anchor.diff:  
     double getMaxIntrinsicHeight(BoxConstraints constraints) {
       return _getIntrinsicHeight(constraints);
  +  }
  +
  +  double computeDistanceToActualBaseline(TextBaseline baseline) {
  +    return defaultComputeDistanceToFirstActualBaseline(baseline);
     }
   
     bool _hasVisualOverflow = false;
  
positive.code:   double getMaxIntrinsicHeight(BoxConstraints constraints) {
      return constraints.constrainHeight();
    }
  
    bool get sizedByParent => true;
  
  
negative.code:       return;
      _startOffset = value;
      if (!_inCallback)
        markNeedsPaint();
    }
  
    double getMinIntrinsicWidth(BoxConstraints constraints) {
  