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); }