code: def _get_or_create_subscription(self):
          
          topic_path = self._get_topic_path()
          subscription_name = '{}-{}-shared'.format(
              PUBSUB_OBJECT_PREFIX, self.name)
          subscription_path = self.subscriber_client.subscription_path(
              self.project, subscription_name)
  
          try:
              self.subscriber_client.get_subscription(subscription_path)
          except google.cloud.exceptions.NotFound:
              logger.info("Creating shared subscription {}".format(
                  subscription_name))
              try:
                  self.subscriber_client.create_subscription(
                      subscription_path, topic=topic_path)
              except google.cloud.exceptions.Conflict:
                  # Another worker created the subscription before us, ignore.
                  pass
  
          return subscription_path
docs: Workers all share the same subscription so that tasks are
          distributed across all workers.