assignmentNotification[0].getPartyReference().setHref(null);
StringWriter out = new StringWriter();
Marshaller marshaller = new Marshaller (out);
marshaller.setValidation(true);
marshaller.marshal(entity);
// fail ("MarshalException expected, because partyReference/@href is use=\"required\"");
}
catch (Exception e) {
// assertTrue(e instanceof ValidationException);