public void GetByIDExceptionTest()
        {
            // Arrange
            IList<Appointment> appointments = new List<Appointment>
            {
                new Appointment() { ID = 1 }
            };

            IAppointmentRepository repository = new AppointmentRepository(appointments);

            // Act
            Appointment result = repository.GetByID(2);
        }
        public void GetByIDTest()
        {
            // Arrange
            IList<Appointment> appointments = new List<Appointment>
            {
                new Appointment() { ID = 1 }
            };

            IAppointmentRepository repository = new AppointmentRepository(appointments);

            // Act
            Appointment result = repository.GetByID(1);

            // Assert
            Assert.AreEqual(1, result.ID);
        }