How to Generate sitemap in laravel

Route::get('sitemap', function(){

    // create new sitemap object
    $sitemap = App::make("sitemap");

    // set cache (key (string), duration in minutes (Carbon|Datetime|int), turn on/off (boolean))
    // by default cache is disabled
    $sitemap->setCache('laravel.sitemap', 3600);

    // check if there is cached sitemap and build new only if is not
    if (!$sitemap->isCached())
    {
         // add item to the sitemap (url, date, priority, freq)
         $sitemap->add(URL::to('/'), '2012-08-25T20:10:00+02:00', '1.0', 'daily');
         $sitemap->add(URL::to('page'), '2012-08-26T12:30:00+02:00', '0.9', 'monthly');

         // add item with translations (url, date, priority, freq, images, title, translations)
         $translations = [
                           ['language' => 'fr', 'url' => URL::to('pageFr')],
                           ['language' => 'de', 'url' => URL::to('pageDe')],
                           ['language' => 'bg', 'url' => URL::to('pageBg')],
                         ];
         $sitemap->add(URL::to('pageEn'), '2015-06-24T14:30:00+02:00', '0.9', 'monthly', [], null, $translations);

         // add item with images
         $images = [
                     ['url' => URL::to('images/pic1.jpg'), 'title' => 'Image title', 'caption' => 'Image caption', 'geo_location' => 'Plovdiv, Bulgaria'],
                     ['url' => URL::to('images/pic2.jpg'), 'title' => 'Image title2', 'caption' => 'Image caption2'],
                     ['url' => URL::to('images/pic3.jpg'), 'title' => 'Image title3'],
                   ];
         $sitemap->add(URL::to('post-with-images'), '2015-06-24T14:30:00+02:00', '0.9', 'monthly', $images);

         // get all posts from db
         $posts = DB::table('posts')->orderBy('created_at', 'desc')->get();

         // add every post to the sitemap
         foreach ($posts as $post)
         {
            $sitemap->add($post->slug, $post->modified, $post->priority, $post->freq);
         }
    }

    // show your sitemap (options: 'xml' (default), 'html', 'txt', 'ror-rss', 'ror-rdf')
    return $sitemap->render('xml');

});