anchor.diff:    if (!Platform.environment.containsKey('UNIT_TEST_ASSETS')) {
       return;
     }
  -  final String assetFolderPath = Platform.environment['UNIT_TEST_ASSETS'];
  +  final String? assetFolderPath = Platform.environment['UNIT_TEST_ASSETS'];
     assert(Platform.environment['APP_NAME'] != null);
     final String prefix = 'packages/${Platform.environment['APP_NAME']}/';
   
  
positive.code: Finder findSubstring(Widget widget, String text) {
    return find.byWidgetPredicate((widget) {
      if (widget is Text) {
        if (widget.data != null) return widget.data.contains(text);
        return widget.textSpan.toPlainText().contains(text);
      } else if (widget is RichText) {
        return widget.text.toPlainText().contains(text);
      } else if (widget is SelectableText) {
        if (widget.data != null) return widget.data.contains(text);
      }
      return false;
    });
  
negative.code:     return find.byWidgetPredicate((widget) =>
          widget is SelectableText &&
          ((widget.data?.contains(text) ?? false) ||
              (widget.textSpan?.toPlainText().contains(text) ?? false)));
    }
  }
  
  