public static function readableSize($bytes, $precision = 1)
    {
        static $units = ['B', 'KB', 'MB', 'GB', 'TB', 'PB'];
        if ($bytes === 0) {
            return '0 '.$units[0];
        }
        $exponent = floor(log($bytes, 1024));
        $value = $bytes / pow(1024, $exponent);

        return round($value, $precision).' '.$units[$exponent];
    }