protected function contentIsFileInfo($file, string $method = 'getStream') : bool
    {
        if (! $file instanceof \SplFileInfo) {
            $message = 'The "%s::%s" expect the file array key to be an instance of "%s". "%s" given';
            $givenType = (is_object($file) ? get_class($file) : gettype($file));

            throw new \RuntimeException(sprintf($message, static::class, $method, \SplFileInfo::class, $givenType));
        }

        return true;
    }