code: public void warn(SourceLocator srcLctr, Node styleNode, Node sourceNode, String msg, Object args[])
            throws TransformerException
    {
  
      String formattedMsg = XSLMessages.createWarning(msg, args);
      ErrorListener errHandler = m_transformer.getErrorListener();
  
      if (null != errHandler)
        errHandler.warning(new TransformerException(formattedMsg, srcLctr));
      else
        System.out.println(formattedMsg);
    }
docs: Warn the user of a problem.
  
  @param styleNode Stylesheet node
  @param sourceNode Source tree node
  @param msg Message text to issue
  @param args Arguments to pass to the message
  @throws XSLProcessorException thrown if the active ProblemListener and XPathContext decide
  the error condition is severe enough to halt processing.
  
  @throws TransformerException
  @xsl.usage internal