anchor.diff:        customTextDirection == other.customTextDirection &&
         locale == other.locale &&
         timeDilation == other.timeDilation &&
  -      platform == other.platform;
  +      platform == other.platform &&
  +      isTestMode == other.isTestMode;
   
     @override
     int get hashCode => hashValues(
  
positive.code:     Locale locale,
      double timeDilation,
      TargetPlatform platform,
    }) {
      return GalleryOptions(
        themeMode: themeMode ?? this.themeMode,
  
negative.code:   }
  }
  
  // Everything below is boilerplate except code relating to time dilation and
  // theme changes.
  // See https://medium.com/flutter/managing-flutter-application-state-with-inheritedwidgets-1140452befe1
  
  class _ModelBindingScope extends InheritedWidget {
  