code: public void startPrefixMapping(String prefix, String uri)
            throws SAXException
    {
      flushStartDoc();
      m_resultContentHandler.startPrefixMapping(prefix, uri);
    }
docs: Receive notification of the start of a Namespace mapping.
  
  <p>By default, do nothing.  Application writers may override this
  method in a subclass to take specific actions at the start of
  each Namespace prefix scope (such as storing the prefix mapping).</p>
  
  @param prefix The Namespace prefix being declared.
  @param uri The Namespace URI mapped to the prefix.
  @throws org.xml.sax.SAXException Any SAX exception, possibly
  wrapping another exception.
  @see org.xml.sax.ContentHandler#startPrefixMapping
  
  @throws SAXException