title: Shopware 6 Production Unable to access plugin services from the container in a unit test
body: <p>I setup a Unit Test in a Shopware custom (static) Plugin following this guide:</p>
  <p><a href="https://developer.shopware.com/docs/guides/plugins/plugins/testing/php-unit" rel="nofollow noreferrer">Shopware documentation</a></p>
  <p>Everything runs fine and I'm able to run a unit test</p>
  <pre><code>class ProductReturnsTest extends TestCase
  {
       use IntegrationTestBehaviour;
       use StorefrontPageTestBehaviour;
  
  public function testConfirmPageSubscriber(): void
  {
      $container = $this-&gt;getKernel()-&gt;getContainer();
      $dd = $container-&gt;get(CustomDataService::class); &lt;== IT BREAKS HERE ServiceNotFoundException: You have requested a non-existent service 
  
      $dd = $container-&gt;get('event_dispatcher'); // WORKS WITH SHOPWARE ALIASES NOT WITH PLUGINS
  }
  }
  </code></pre>
  <p>I can make <code>container-&gt;get</code> on any shopware alias but as soon I try to recall and get from the container any service decleared in any xml of any 3th party plugin, i get</p>
  <pre><code> ServiceNotFoundException: You have requested a non-existent service &quot;blabla&quot;
  </code></pre>
  <p>What is wrong ?</p>