//Create XmlEventReader (what the JaxbPortalDataHandlerService has)
final XMLInputFactory xmlInputFactory = xmlUtilities.getXmlInputFactory();
final XMLEventReader xmlEventReader = xmlInputFactory.createXMLEventReader(inputResource.getInputStream());
final Node sourceNode = xmlUtilities.convertToDom(xmlEventReader);
final DOMSource source = new DOMSource(sourceNode);
final DOMResult result = new DOMResult();
xsltDataUpgrader.upgradeData(source, result);