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");
}
