docs: function setLanguage(req) {
          var host = req.info.host;
  
          // hack fix for m.reviews, m.fr, m.es, etc.
          if (host.substring(0, 2) === 'm.') {
              req.app.isLegacyMobile = true;
              host = host.substring(2);
          }
  
          var subdomain = host.substring(0, 2);
  
          // either at language-based subdomain or we use english
          req.app.lang = (host.charAt(2) === '.' && langSubdomains.indexOf(subdomain) >= 0) ?
              subdomain : 'en';
      }