/// <summary>
            /// Removes reservation of the gift card from a given terminal so it can be used on other terminals.
            /// </summary>
            /// <param name="request">The <see cref="UnlockGiftCardRealtimeRequest"/> request.</param>
            /// <returns>The <see cref="NullResponse"/> response.</returns>
            private static NullResponse UnlockGiftCard(UnlockGiftCardRealtimeRequest request)
            {
                var transactionClient = new TransactionService.TransactionServiceClient(request.RequestContext);

                transactionClient.UnlockGiftCard(request.GiftCardId);

                return(new NullResponse());
            }
            /// <summary>
            /// Unlock the gift card.
            /// </summary>
            /// <param name="request">The request.</param>
            /// <returns>
            /// A response containing the gift card.
            /// </returns>
            private static NullResponse UnlockGiftCard(UnlockGiftCardServiceRequest request)
            {
                if (request == null)
                {
                    throw new ArgumentNullException("request");
                }

                var unlockRequest = new UnlockGiftCardRealtimeRequest(request.GiftCardId);

                request.RequestContext.Execute <NullResponse>(unlockRequest);

                return(new NullResponse());
            }