code: public Object getDocumentRoot(MatchSpaceKey msg) 
      throws BadMessageFormatMatchingException
    {
      if (tc.isAnyTracingEnabled() && tc.isEntryEnabled())
        tc.entry(cclass, "getDocumentRoot", msg);
  
      Object docRoot = null;
      
      if (tc.isAnyTracingEnabled() && tc.isEntryEnabled())
        tc.exit(cclass, "getDocumentRoot", docRoot);    
      return docRoot;
    }
docs: Get a DOM document root from a message.
  
  @param childNodeList
  @return
  @throws BadMessageFormatMatchingException