anchor.diff:  
   class ThemedImageIcon extends StatelessWidget {
     const ThemedImageIcon({
  -    @required this.lightModeAsset,
  -    @required this.darkModeAsset,
  +    required this.lightModeAsset,
  +    required this.darkModeAsset,
     });
   
     final String lightModeAsset;
  
positive.code: 
  class AssetImageIcon extends StatelessWidget {
    const AssetImageIcon({
      @required this.asset,
      double height,
      double width,
    })  : _width = width,
          _height = height;
  
    final String asset;
    final double _height;
    final double _width;
  
    double get width => _width ?? defaultIconSize;
    double get height => _height ?? defaultIconSize;
  
negative.code: }
  
  class IconKind {
    const IconKind(this.name, this.icon, [AssetImageIcon? abstractIcon])
        : abstractIcon = abstractIcon ?? icon;
  
    static IconKind classIcon = const IconKind(
  