protected function writeError(OutputInterface $output, \Exception $error)
    {
        if (null !== $this->getHelperSet() && $this->getHelperSet()->has('formatter')) {
            $message = $this->getHelperSet()->get('formatter')->formatBlock($error->getMessage(), 'error');
        } else {
            $message = '<error>'.$error->getMessage().'</error>';
        }

        $output->writeln($message);
    }