// unmarshal a document, just to marshal it back again.
JAXBElement poe = (JAXBElement)context.createUnmarshaller().unmarshal(
new File(args[0]));
// we don't need to check the return value, because the unmarshal
// method should haven thrown an exception if anything went wrong.
PurchaseOrderType po = (PurchaseOrderType)poe.getValue();
// Here's the real meat.
// we configure marshaller not to print out xml decl,
// we then print out XML decl plus stylesheet header on our own,