code: def _handle_is_dag_stopped(self, request):
          
          return Response(success=True,
                          uid=request.uid,
                          payload={
                              'is_stopped': request.payload['dag_name'] in self._stop_dags
                          })
docs: The handler for the dag_stopped request.
  
          The dag_stopped request checks whether a dag is flagged to be terminated.
  
          Args:
              request (Request): Reference to a request object containing the
                                 incoming request. The payload has to contain the
                                 following fields:
                                  'dag_name': the name of the dag that should be checked
  
          Returns:
              Response: A response object containing the following fields:
                            - is_stopped: True if the dag is flagged to be stopped.