code: def CELERY_RESULT_BACKEND(self):
          
  
          # allow specify directly
          configured = get('CELERY_RESULT_BACKEND', None)
          if configured:
              return configured
  
          if not self._redis_available():
              return None
  
          host, port = self.REDIS_HOST, self.REDIS_PORT
  
          if host and port:
              default = "redis://{host}:{port}/{db}".format(
                      host=host, port=port,
                      db=self.CELERY_REDIS_RESULT_DB)
  
          return default
docs: Redis result backend config