Xml error This page contains the following errors: - php

Question

php code creates xml and displays on screen. Unfortunately, I get an error and I don't know how to fix it.
This page contains the following errors:
error on line 2 at column 1: Extra content at the end of the document
Below is a rendering of the page up to the first error.
The structure of the xml file itself looks good after saving
<Movies>
<movie movie_id="5467">
<Title>The Campaign</Title>
<Year>2012</Year>
<Genre>The Campaign</Genre>
<Ratings>6.2</Ratings>
</movie>
</Movies>
I need to display the same code on screen after calling php.
$dom = new DOMDocument();
$dom->encoding = 'utf-8';
$dom->xmlVersion = '1.0';
$dom->formatOutput = true;
$xml_file_name = 'movies_list.xml';
$root = $dom->createElement('Movies');
$movie_node = $dom->createElement('movie');
$attr_movie_id = new DOMAttr('movie_id', '5467');
$movie_node->setAttributeNode($attr_movie_id);
$child_node_title = $dom->createElement('Title', '<![CDATA[The Campaign]]');
$movie_node->appendChild($child_node_title);
$child_node_year = $dom->createElement('Year', 2012);
$movie_node->appendChild($child_node_year);
$child_node_genre = $dom->createElement('Genre', '<![CDATA[The Campaign]]');
$movie_node->appendChild($child_node_genre);
$child_node_ratings = $dom->createElement('Ratings', 6.2);
$movie_node->appendChild($child_node_ratings);
$root->appendChild($movie_node);
$dom->appendChild($root);
Header('Content-type: text/xml');
echo $xml_file_name->asXML();
Please help me in solving. I looked for many solutions but nothing helped.