private function registerNotifyService()
    {
        $this->singleton(Contracts\Notify::class, function ($app) {
            /**  @var \Illuminate\Config\Repository  $config  */
            $config = $app['config'];

            return new Notify(
                $app[Contracts\SessionStore::class],
                $config->get('notify.session.prefix', 'notifier')
            );
        });
    }