public void Init()
 {
     _questions = new QuestionRepository(1);
     _popQuestion = new Question(QuestionCategory.Pop, PopQuestionText0);
     new Question(QuestionCategory.Pop, PopQuestionText0);
     new Question(QuestionCategory.Rock, RockQuestionText);
 }
        public void throw_a_NullReferenceException_when_trying_to_remove_firstQuestion_from_an_empty_repository()
        {
            var questionRepository = new QuestionRepository(0);

            questionRepository.GetNextQuestionBy(QuestionCategory.Pop);
        }