protected function createStackDriver()
    {
        $determiners = (new Collection((array) $this->app['config']['localize-middleware']['driver']))
            ->filter(function ($driver) {
                return $driver !== 'stack';
            })
            ->map(function ($driver) {
                return $this->driver($driver)->setFallback(null);
            });

        return (new Determiners\Stack($determiners))
            ->setFallback($this->app['config']['app']['fallback_locale']);
    }