Verify and get gift card balances

using Gr4vy;
using Gr4vy.Models.Components;
using System.Collections.Generic;

var sdk = new Gr4vySDK(
    id: "example",
    server: SDKConfig.Server.Sandbox,
    bearerAuthSource: Auth.WithToken(privateKey),
    merchantAccountId: "default"
);

var res = await sdk.GiftCards.Balances.ListAsync(giftCardBalanceRequest: new GiftCardBalanceRequest() {
    Items = new List<Item>() {
        Item.CreateGiftCardStoredRequest(
            new GiftCardStoredRequest() {
                Id = "356d56e5-fe16-42ae-97ee-8d55d846ae2e",
            }
        ),
    },
});

// handle response

{
  "items": [
    {
      "type": "gift-card",
      "id": "356d56e5-fe16-42ae-97ee-8d55d846ae2e",
      "merchant_account_id": "default",
      "bin": "412345",
      "sub_bin": "554",
      "last4": "1234",
      "currency": "AUD",
      "expiration_date": "2013-07-16T19:23:00.000+00:00",
      "balance": 1299,
      "balance_error_code": "incorrect_currency",
      "balance_raw_error_code": "10363",
      "balance_raw_error_message": "This currency is not supported by the merchant."
    }
  ]
}