public IHttpActionResult GetFilesByStudentId(int id)
        {
            var files = fileRepo.GetFilesByStudentId(id).ToList();

            if (!files.Any())
            {
                return(Content(HttpStatusCode.NotFound, "List is empty"));
            }
            return(Ok(files));
        }
        public void GetFilesByStudentIdTest()
        {
            UnitOfWork unit = new UnitOfWork();
            FileRepo   repo = unit.FileRepo();


            var expected = 2;

            var actual = repo.GetFilesByStudentId(7).First().FileId;

            Assert.AreEqual(expected, actual);
        }