code: public void setErrorListener(ErrorListener listener)
            throws IllegalArgumentException
    {
  
      synchronized (m_reentryGuard)
      {
        if (listener == null)
          throw new IllegalArgumentException(XSLMessages.createMessage(XSLTErrorResources.ER_NULL_ERROR_HANDLER, null)); //"Null error handler");
  
        m_errorHandler = listener;
      }
    }
docs: Set the error event listener.
  
  @param listener The new error listener.
  @throws IllegalArgumentException if