code: public void startElement(String namespaceURI, String localName,
                               String qName, Attributes atts) throws SAXException {
          trace("startElement:" + localName + "~" + qName);
          Element newElement = createElement(namespaceURI, qName, atts);
          appendNode(newElement);
          currentElement = newElement;
      }
docs: ContentHandler method
  @throws SAXException