code: def serve_listing(self, environ):
          
          result = {'fixed': self.warcserver.list_fixed_routes(),
                    'dynamic': self.warcserver.list_dynamic_routes()
                   }
  
          return WbResponse.json_response(result)
docs: Serves the response for WARCServer fixed and dynamic listing (paths)
  
          :param dict environ: The WSGI environment dictionary for the request
          :return: WbResponse containing the frontend apps WARCServer URL paths
          :rtype: WbResponse