public void ShouldAddQuestionResultAndAnswersWhenAddingQuestionResult()
        {
            var questionResult = new QuestionResult();
            var answer = new Answer(true, DateTime.Now, TimeSpan.FromSeconds(1), null);
            questionResult.AddAnswer(answer);

            _objectUnderTest.AddQuestionResult(questionResult);

            _serviceMock.Verify(p => p.AddQuestionResult(questionResult));
            _serviceMock.Verify(p => p.AddAnswer(answer));
        }
        public void AddAnswer(Answer answer)
        {
            answer.QuestionResultId = Id;
            answer.QuestionResult = this;
            Answers.Add(answer);

            if (answer.IsCorrect) NumberOfCorrectAnswers++;
            else NumberOfIncorrectAnswers++;

            Duration += answer.Duration;
        }