public function registerMetabox()
    {
        $this->app->bind('metabox', function ($app) {
            $resource = new MetaboxResource(
                $app->bound('league.fractal') ? $app['league.fractal'] : new Manager(),
                new ArraySerializer(),
                new MetaboxTransformer()
            );

            return new Factory($app, $app['action'], $app['filter'], $resource);
        });
    }