public static function toBytes(String $data) : Float
    {
        $number = substr($data, 0, -2);

        switch( strtoupper(substr($data, -2)) )
        {
            case 'KB': return $number * 1024;
            case 'MB': return $number * pow(1024, 2);
            case 'GB': return $number * pow(1024, 3);
            case 'TB': return $number * pow(1024, 4);
            case 'PB': return $number * pow(1024, 5);

            default  : return $data;
        }
    }