public ActionResult <Answer> AddAnswer(int id, AnswerDTO answer)
        {
            var user = _userRepository.GetById(answer.userId);

            if (user == null)
            {
                return(NotFound());
            }

            Answer newAnswer = new Answer(answer.Body, user);

            _postRepository.AddAnswer(id, newAnswer);
            _postRepository.SaveChanges();

            return(Ok(newAnswer));
        }