public Tuple <Vendor, SpotReservation> GetReservation(string spotId, string rentalDate, string ignoredVendorId = null)
        {
            var vendorReserved = GetVendorWhoReservedSpot(spotId, ignoredVendorId);

            if (vendorReserved != null)
            {
                return(new Tuple <Vendor, SpotReservation>(vendorReserved, null));
            }
            var oneTimeReservation = SpotReservationDbClient.Get(new SpotReservation
            {
                SpotId     = spotId,
                RentalDate = rentalDate
            },
                                                                 true).Result;

            if (oneTimeReservation != null)
            {
                return(new Tuple <Vendor, SpotReservation>(null, oneTimeReservation));
            }
            return(null);
        }