writer = xof.createXMLStreamWriter(streamResult.getOutputStream(), "UTF-8");
writer = new PrettyPrintXMLStreamWriter(writer);
final XoXMLStreamWriter w = new XoXMLStreamWriterImpl(writer);
try {
w.writeStartDocument("UTF-8", null);
// write xsi:type if there is no default root element for this type
final RuntimeContext context = new RuntimeContext((ExtendedMarshaller) null);