anchor.diff:            totalHeight,
           ),
           _minSizes = modifyMinSizesToIncludeFirstHeader(minSizes, headers),
  -        super(key: key) {
  -    if (minSizes != null) {
  -      assert(minSizes.length == children.length);
  -    }
  -  }
  +        super(key: key);
   
     /// The headers that will be laid out above each corresponding child in
     /// [children].
  
positive.code: // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  // @dart=2.9
  
  import 'package:flutter/material.dart';
  
  
negative.code: 
  class FlexSplitColumn extends StatelessWidget {
    FlexSplitColumn({
      Key? key,
      required this.totalHeight,
      required this.headers,
      required List<Widget> children,
      required List<double> initialFractions,
      required List<double> minSizes,
    })  : assert(children.length >= 2),
          assert(initialFractions.length >= 2),
          assert(children.length == initialFractions.length),
          assert(minSizes.length == children.length),
          _children = buildChildrenWithFirstHeader(children, headers),
          _initialFractions = modifyInitialFractionsToIncludeFirstHeader(
            initialFractions,
  