public ActionResult <ParkingEntry> Enter([FromBody] string registration)
        {
            var value = new ParkingEntry
            {
                ParkingEntryId      = Guid.NewGuid(),
                ParkingRegistration = registration,
                EntryTime           = DateTime.Now
            };

            return
                (_parkingEntryRepository
                 .AddOrUpdate(value));
        }
 public Invoice CalculateTotals(ParkingEntry entry)
 {
     return(CalculateTotals(entry.EntryTime, entry.ExitTime));
 }