code: public void processingInstruction(String target, String data)
  			throws SAXException {
  		append(m_doc.createProcessingInstruction(target, data));
  	}
docs: Receive notification of a processing instruction.
  
  <p>
  The Parser will invoke this method once for each processing instruction
  found: note that processing instructions may occur before or after the
  main document element.
  </p>
  
  <p>
  A SAX parser should never report an XML declaration (XML 1.0, section
  2.8) or a text declaration (XML 1.0, section 4.3.1) using this method.
  </p>
  
  @param target
  The processing instruction target.
  @param data
  The processing instruction data, or null if none was supplied.