public void serialize(DBBroker broker, Receiver handler) {
            try {
                AttrList attribs = new AttrList();
                if (event == XMLStreamReader.START_ELEMENT || event == XMLStreamReader.END_ELEMENT) {
                    String ev = event == XMLStreamReader.START_ELEMENT ? "start" : "end";
                    attribs.addAttribute(ATTR_EVENT, ev);
                }
                attribs.addAttribute(ATTR_REF, refChild.getNodeId().toString());
                handler.startElement(ELEMENT_DELETE, attribs);
                handler.endElement(ELEMENT_DELETE);
            } catch (SAXException e) {