public function output(string $output, string $identifier): void
    {
        if (empty($output)) {
            return;
        }

        $lines = explode("\n", $output);

        foreach ($lines as $line) {
            // color lines containing "[WARN]" or "[DEBUG]"
            if (mb_strpos($line, '[WARN]') !== false) {
                $line = '<fg=black;bg=yellow>' . $line . '</fg=black;bg=yellow>';
            } elseif (mb_strpos($line, '[DEBUG]') !== false) {
                $line = '<comment>' . $line . '</comment>';
            }

            $this->write($identifier . '> ');
            $this->writeln($line);
        }
    }