public void testUpdate()
        {
            // Arrange
            int count = repo.All().Count();

            repo.Add(entity);
            this.repo.SaveChanges();

            Assert.Null(repo.GetByDetails(99, "ס"));


            Assert.AreEqual(count + 1, repo.All().Count());
            entity.ClassNumber = 99;


            // Act
            repo.Update(entity);
            repo.SaveChanges();

            // Assert

            Assert.NotNull(repo.GetByDetails(99, "ס"));
            this.repo.HardDelete(entity);
            this.repo.SaveChanges();
        }