public void AddAttendance_Succeeds()
        {
            DateTime  date       = DateTime.Today;
            TimeOfDay timeOfDay  = TimeOfDay.AVOND;
            int       activityId = 7;
            int       userId     = 1;

            _dayActivityRepository.Setup(d => d.GetCustomDayActivity(date, timeOfDay, activityId)).Returns(_dummyDBContext.DayActivity1);
            _userRepository.Setup(d => d.GetById(userId)).Returns(_dummyDBContext.U4);

            ActionResult <Attendance> actionResult = _controller.Add(date, timeOfDay, activityId, userId);
            var        response      = actionResult?.Result as OkObjectResult;
            Attendance newAttendance = response?.Value as Attendance;

            Assert.Equal("Alihan", newAttendance.User.FirstName);

            _dayActivityRepository.Verify(a => a.SaveChanges(), Times.Once());
        }