anchor.diff:          // We only need to correct if the leading child actually has a
           // paint extent.
           if (firstChildScrollOffset < -precisionErrorTolerance) {
  -          print('RRL_2 scrollOffsetCorrection');
             geometry = SliverGeometry(
               scrollOffsetCorrection: -firstChildScrollOffset,
             );
  
positive.code:     crossAxisIndex = parentData.crossAxisIndex;
    }
  }
  
  void log(Object message) {
    print(message);
  }
  
negative.code:       }
        // We should be able to destroy children with null layout offset safely,
        // because they are likely outside of viewport
        collectGarbage(leadingChildrenWithoutLayoutOffset, 0);
        // If can not find a valid layout offset, start from the initial child.
        if (firstChild == null) {
  