public List <Appointment> GetAppointmentsByMonth(int month)
 {
     return(TestDatabase.GetAppointments().Where(a => a.StartDate.Month == month || a.EndDate.Month == month).ToList());
 }
 public Appointment GetAppointment(int Id)
 {
     return(TestDatabase.GetAppointments().Where(a => a.AppointmentId == Id).FirstOrDefault());
 }