public function get_file_extensions()
 {
     $show_model = new \Dicentis\Podcast_Post_Type\Dipo_Episode_Model();
     return $show_model->get_file_extensions();
 }
<?php

namespace Dicentis\Feed;

/**
 * RSS2 Feed Template for displaying RSS2 Posts feed.
 *
 * @package WordPress
 */
$feed = new Dipo_RSS_Model();
$feed->init_show();
$show = $feed->get_show();
$episode = new \Dicentis\Podcast_Post_Type\Dipo_Episode_Model();
header('Content-Type: application/rss+xml; charset=' . get_option('blog_charset'), true);
$more = 1;
echo '<?xml version="1.0" encoding="' . get_option('blog_charset') . '"?' . '>';
?>
<rss version="2.0"
	xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd"
	xmlns:content="http://purl.org/rss/1.0/modules/content/"
	xmlns:wfw="http://wellformedweb.org/CommentAPI/"
	xmlns:dc="http://purl.org/dc/elements/1.1/"
	xmlns:atom="http://www.w3.org/2005/Atom"
	xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
	xmlns:slash="http://purl.org/rss/1.0/modules/slash/"
	<?php 
do_action('rss2_ns');
?>
>
<channel>
	<title><?php