*/
public Notification requestNotification(String serialNumber) throws CheckoutException {
NotificationHistoryRequest request = new NotificationHistoryRequest();
request.setSerialNumber(serialNumber);
// this is a specific notification domain object.
return (Notification)postRequest(request.toJAXB());
}
/**
* Fetches the order summaries which correspond to the specified
* {@code googleOrderNumbers}. They will reflect the current state of those