request_stack missing

[Ernestopheles]

<?php

declare(strict_types=1);


namespace Nahati\ContaoIsotopeStockBundle\Tests\Integration\EventListener;


use Contao\TestCase\ContaoTestCase;
use Isotope\Model\ProductCollection\Cart;


/**
 * Test the UpdateItemInCollectionListener class.
 */
class UpdateItemInCollectionListenerSimplifiedTest extends ContaoTestCase
{
    protected function setUp(): void
    {
        parent::setUp();
    }


    public function testUpdateItemInCollectionListenerReturnsQuantityZeroWhenProductIsSoldout(): void
    {
        $cart = new Cart();
    }
}

ergibt:
Symfony\Component\DependencyInjection\Exception\Se rviceNotFoundException: You have requested a non-existent service "request_stack".

Was fehlt?