public void AddShiftMissingEmployeeId()
        {
            ProposedShift proposedShift = new ProposedShift()
            {
                dateTime = new DateTimeOffset(),
                ShiftId  = new Guid()
            };

            var mockRepository = new Mock <INowRepository>();
            var controller     = new ScheduleController(mockRepository.Object);


            var response = controller.AddShift(proposedShift);

            Assert.Equal("Invalid Data", response.Value);
        }