Integrate this with functional test

[desarrolla2]

How i must to use this with functional test?

I try diferent things but nothing works, for example:

        $app['app.mobile.detect'] = $app->share(
            function () use ($app) {
               return new \Mobile_Detect([], $app['request_stack']->getCurrentRequest()->headers->get('User-Agent'));
            }
        );

        $app['app.mobile.detect'] = $app->share(
            function () use ($app) {
               return new \Mobile_Detect([], $app['request']->headers->get('User-Agent'));
            }
        );