private ParkingSession(long id, Entrance entrance, Vehicle vehicle, Valet valet, ParkingPlace parkingPlace, ParkingPeriod parkingPeriod)
        {
            _id = id;

            Entrance = entrance;
            Vehicle = vehicle;
            Valet = valet;
            ParkingPlace = parkingPlace;
            ParkingPeriod = parkingPeriod;
        }
 public void End(Exit exit)
 {
     Exit = exit;
     ParkingPeriod = new ParkingPeriod(ParkingPeriod.Start, DateTime.Now);
 }