private static function injectDeprecatedConfig(array $config, array $extra)
    {
        foreach (self::$deprecatedOptions as $key => $deprecatedKey) {
            if (\array_key_exists($deprecatedKey, $extra) && !\array_key_exists($key, $config)) {
                $config[$key] = $extra[$deprecatedKey];
            }
        }

        return $config;
    }