public Appointment AddAppointment(string id, string patientId, string diagnostic, bool isEmergency)
{
if (patientRepository.Contains(patientId) == false)
{
throw new RepositoryException("Specified patient does not exist");
}
Appointment appointment = new Appointment();
appointment.ID = id;
appointment.PatientID = patientId;
appointment.Diagnostic = diagnostic;
appointment.IsEmergency = isEmergency;
appointment.Validate();
appointmentRepository.Add(appointment);
patientRepository.AddAppointment(id, patientId);
return(appointment);
}