public NotificationHandler(DpApi client, HospitalContext db = null)
{
_db = db ?? new HospitalContext();
_visitRepo = new VisitRepository(_db);
_mappingRepo = new DoctorMappingRepository(_db);
_scheduleRepo = new ScheduleRepository(_db);
_client = client;
_scheduleManager = new ScheduleManager(_db, _client);
_visitManager = new VisitManager(_db, _client, _scheduleManager);
}