Element parentNode = (Element)domParent.getNode();
// parentNode.setAttributeNS(XML_NS, "xmlns:mdssi", XML_DIGSIG_NS);
Document doc = parentNode.getOwnerDocument();
for (String sourceId : this.sourceIds) {
RelationshipReferenceDocument relRef = RelationshipReferenceDocument.Factory.newInstance();
relRef.addNewRelationshipReference().setSourceId(sourceId);
Node n = relRef.getRelationshipReference().getDomNode();
n = doc.importNode(n, true);
parentNode.appendChild(n);
}
}