php - Save property type int google datastore

How can I define the property type, when I save a record into Google Datastore with PHP?

version should be type: Integer

color should be type: String

description should be type: Text (I want to save long text there)

created should be type: Date and time

and cardatas should be type Array or Text,

what is the best here for JSON datas?: Array or Text

 $datastore = new DatastoreClient();
    $key = 'protCarDatas';
    $time = date(DATE_RFC3339);
    $savedata = $datastore->entity(
        $key,
           [
             'version' => $version,
             'color' => $color,
             'description' => $desc,
             'created' => $time,
             'cardatas' => $fullCardDataJsonString
           ],
           ['excludeFromIndexes' => ['cardatas']]
    );

    $datastore->insert($savedata); 
Copy code

Thanks for help!