code: def create_url_adapter(self, request: Optional[BaseRequestWebsocket]) -> Optional[MapAdapter]:
          
          if request is not None:
              host = request.host
              return self.url_map.bind_to_request(
                  request.scheme, host, request.method, request.path, request.query_string,
              )
  
          if self.config['SERVER_NAME'] is not None:
              return self.url_map.bind(
                  self.config['PREFERRED_URL_SCHEME'], self.config['SERVER_NAME'],
              )
          return None
docs: Create and return a URL adapter.
  
          This will create the adapter based on the request if present
          otherwise the app configuration.