code: def require_authentication(self, realm, environ):
          
          realm_entry = self._get_realm_entry(realm)
          if realm_entry is None:
              _logger.error(
                  'Missing configuration simple_dc.user_mapping["{}"] (or "*"): '
                  "realm is not accessible!".format(realm)
              )
          return realm_entry is not True
docs: Return True if this realm requires authentication (grant anonymous access otherwise).