public void change_status_test()
        {
            // Arrange
            const long userId = 8;
            const long updatedBy = 1;
            const bool isActive = true;
            var userRepository = new Mock<IRepository<User>>();
            userRepository.Setup(x => x.FindOne(It.IsAny<Expression<Func<User, bool>>>())).Returns(new User { Id = userId });

            // Act
            var userService = new UserService(userRepository.Object);
            var user = userService.ChangeStatus(userId, updatedBy, isActive);

            // Assert
            Assert.NotNull(user);
            userRepository.Verify(x => x.Update(It.IsAny<User>()), Times.Once);
            userRepository.Verify(x => x.SaveChanges(), Times.AtLeastOnce);
        }