code: public void comment(char ch[], int start, int length) throws SAXException
    {
  
      if (m_insideDTD)      // ignore comments if we're inside the DTD
        return;
  
      charactersFlush();
  
      // %OPT% Saving the comment string in a Vector has a lower cost than
      // saving it in DTMStringPool.
      m_values.addElement(new String(ch, start, length));
      int dataIndex = m_valueIndex++;
  
      m_previous = addNode(DTM.COMMENT_NODE, DTM.COMMENT_NODE,
                           m_parents.peek(), m_previous, dataIndex, false);
    }
docs: Report an XML comment anywhere in the document.
  
  <p>This callback will be used for comments inside or outside the
  document element, including comments in the external DTD
  subset (if read).</p>
  
  @param ch An array holding the characters in the comment.
  @param start The starting position in the array.
  @param length The number of characters to use from the array.
  @throws SAXException The application may raise an exception.