private void startDocument() throws SAXException {
        getContentHandler().startDocument();
        getContentHandler().startPrefixMapping(EMPTY_STRING, NAMESPACE);
        getContentHandler().startPrefixMapping(XSI, XMLSCHEMA_INSTANCE);
        getContentHandler().startElement(NAMESPACE, XML_ELEMENT_ROOT, XML_ELEMENT_ROOT, ROOT_ATTS);
    }
Outputs a data element if required using the current match or another
stored match.
stroom-pipeline/src/main/java/stroom/pipeline/xml/converter/ds3/DS3Parser.java