public static function getReadableSize($bytes)
    {
        $unit = ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];
        $exp = floor(log($bytes, 1024)) | 0;

        return round($bytes / (pow(1024, $exp)), 2) . " $unit[$exp]";
    }