14. The data processing device of claim 13 wherein the associations are indicative of updates to the data in the markup documents, the marshalling further comprising overwriting data corresponding to the updates and avoiding overwriting data extraneous to the updates in the modified managed objects.
15. The data processing device of claim 14 wherein the markup documents are XML objects which define an XML content object tree, the managed objects are JAXB objects in a JAXB content tree, and the associations are indicative of relations between the content tree of managed objects and the objects in the XML content object tree, wherein the marshaller is further operable to perform a lossless update of the XML objects from the modified managed objects, lossless updating further comprising retaining values of unmodified attributes and nodes in the XML objects.