anchor.diff:  /// The benefit of this approach is that icons can be const objects and tests
   /// of code that uses icons can run on the Dart VM.
   
  -// @dart=2.9
  -
   library icons;
   
   import 'package:flutter/material.dart';
  
positive.code: 
  class ThemedImageIcon extends StatelessWidget {
    const ThemedImageIcon({
      @required this.lightModeAsset,
      @required this.darkModeAsset,
    });
  
    final String lightModeAsset;
  
negative.code: }
  
  class IconKind {
    const IconKind(this.name, this.icon, [AssetImageIcon? abstractIcon])
        : abstractIcon = abstractIcon ?? icon;
  
    static IconKind classIcon = const IconKind(
  