XML : How to add comment in sitemap file

I want to add comment tag in my manually generated XML sitemap like this:

  <?xml version="1.0" encoding="UTF-8"?>  <urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">    <!-- Comment -->    <url>      <loc>http://example.com</loc>    </url>  </urlset>    

Is it possible?