protected function addSslOptions($dsn, array $config)
    {
        foreach (['sslmode', 'sslcert', 'sslkey', 'sslrootcert'] as $option) {
            if (isset($config[$option])) {
                $dsn .= ";{$option}={$config[$option]}";
            }
        }

        return $dsn;
    }