anchor.diff:    }
   
     void _noThanksPressed({
  -    @required String message,
  -    @required BuildContext context,
  +    required String message,
  +    required BuildContext context,
     }) async {
       await server.setSurveyActionTaken();
  -    Notifications.of(context).dismiss(message);
  +    Notifications.of(context)!.dismiss(message);
     }
   
     void _takeSurveyPressed({
  -    @required String surveyUrl,
  -    @required String message,
  -    @required BuildContext context,
  +    required String surveyUrl,
  +    required String message,
  +    required BuildContext context,
     }) async {
       await launchUrl(surveyUrl, context);
       await server.setSurveyActionTaken();
  -    Notifications.of(context).dismiss(message);
  +    Notifications.of(context)!.dismiss(message);
     }
   }
   
  
positive.code: 
      final currentTimeMs = DateTime.now().millisecondsSinceEpoch;
      final activeSurveyRange = Range(
        _cachedSurvey.startDate.millisecondsSinceEpoch,
        _cachedSurvey.endDate.millisecondsSinceEpoch,
      );
      return activeSurveyRange.contains(currentTimeMs);
    }
  
    Future<DevToolsSurvey> _fetchSurveyContent() async {
      try {
        final response = await get(_metadataUrl);
        if (response.statusCode == 200) {
  
negative.code:     return DevToolsSurvey._(id, startDate, endDate, title, surveyUrl);
    }
  
    final String? id;
  
    final DateTime? startDate;
  
    final DateTime? endDate;
  
    final String? title;
  
    final String? url;
  }
  