Please improve PageSetup documentation

[357up]

Hello!

PageSetup documentation mentions that paper_size parameter expects string. However, it does not mention what kind of string in what kind of format it expects exactly.
I have been trying for several hours to figure this out without any luck.

$pageSetup = new PageSetup([
    "paper_size" => "?", // <- tried lover case a4 and upercase A4 and letter and 297x210 and 27x11.69 nothing works.
    "print_quality" => 600,
    "print_gridlines" => false
]);

Also, the API does not respond with anything remotely useful:

[19-Nov-2020 12:22:35 Europe/Riga] PHP Fatal error:  Uncaught Aspose\Cells\Cloud\ApiException: [400] Client error: `POST https://api.aspose.cloud/v3.0/cells/sample.xlsx/worksheets/Offre/pagesetup` resulted in a `400 Bad Request` response:
{"RequestId":"Root=1-5fb64767-5831fcb6651996981ea922c4","Error":{"Code":"Fail","Message":"PostPageSetup fails. (Requeste (truncated...)
 in /var/www/aspose/webspaceroot/vendor/aspose/cells-sdk-php/lib/Api/CellsApi.php:30005
Stack trace:
#0 /var/www/aspose/webspaceroot/vendor/aspose/cells-sdk-php/lib/Api/CellsApi.php(29976): Aspose\Cells\Cloud\Api\CellsApi->cellsPageSetupPostPageSetupWithHttpInfo('sample.xlsx', 'Offre', Object(Aspose\Cells\Cloud\Model\PageSetup), NULL, NULL)
#1 /var/www/aspose/webspaceroot/public/cloud.php(120): Aspose\Cells\Cloud\Api\CellsApi->cellsPageSetupPostPageSetup('sample.xlsx', 'Offre', Object(Aspose\Cells\Cloud\Model\PageSetup), NULL, NULL)
#2 /var/www/aspose/webspaceroot/public/cloud.php(177): App\apiTest->doPageSetup('sample.xlsx', 2, Object(Aspose\Cells\Cloud\Model\PageSetup))
#3 {main}
  thrown in /var/www/aspose/webspaceroot/vendor/aspose/cells-sdk-php/lib/Api/CellsApi.php on line 30005

I would hope this get's improved.