public void PaymentUpdateMerchantReference() { string paymentToken = null; var authorization = authorizationApi.AuthorizationCreateToken(); paymentToken = "001.u0hglki77ko70iuavgnb31vo2qq4ehold53brkdngfj9l73f"; var response = instance.PaymentGetByToken(paymentToken); var reference = new MerchantReference("new_merchan_order_id_1234"); instance.PaymentUpdateMerchantReference(response.Id, reference); response = instance.PaymentGetByToken(paymentToken); Assert.IsInstanceOf <Payment>(response, "response is Payment"); }