silverstripe-framework/tests/php/i18n/i18nTest/_fakewebroot/i18nothermodule/code/i18nTestModuleDecorator.php

<?php

use SilverStripe\ORM\DataExtension;

class i18nTestModuleExtension extends DataExtension
{

    public static $db = [
        'MyExtraField' => 'Varchar'
    ];
}