docs: def get_language(self):
          """
          Return a locale code we support on the site using the
          user's Accept-Language header to determine which is best. This
          mostly follows the RFCs but read bug 439568 for details.
          """
          if 'lang' in self.request.GET:
              lang = self.request.GET['lang'].lower()
              if lang in settings.LANGUAGE_URL_MAP:
                  return settings.LANGUAGE_URL_MAP[lang]
  
          if self.request.META.get('HTTP_ACCEPT_LANGUAGE'):
              best = self.get_best_language(
                  self.request.META['HTTP_ACCEPT_LANGUAGE'])
              if best:
                  return best
          return settings.LANGUAGE_CODE