public ActionResult GetSiteMap()
        {
            using (var dataBase = new ApplicationDbContext())
            {
                var notDeletedMessages = dataBase.Messages
                                         .Where(message => !message.IsDeleted)
                                         .OrderByDescending(message => message.Date)
                                         .ToList();

                var    sitemapGenerator = new SitemapGenerator(notDeletedMessages);
                var    sitemapNodes     = sitemapGenerator.GetSitemapNodes(this.Url);
                string xml = sitemapGenerator.GetSitemapDocument(sitemapNodes);
                return(this.Content(xml, "text/xml", Encoding.UTF8));
            }
        }