getRobotoffQuestionsForProduct method Null safety

Implementation

Future<List<RobotoffQuestion>> getRobotoffQuestionsForProduct() async {
  final RobotoffQuestionResult result =
      await OpenFoodAPIClient.getRobotoffQuestionsForProduct(
    _barcode,
    ProductQuery.getLanguage().code,
    count: 3,
  );
  return result.questions ?? <RobotoffQuestion>[];
}