def METHOD_NAME(self):
    if self._sub is None:
        METHOD_NAME = pymqi.Subscription(self.check.queue_manager)
        # https://dsuch.github.io/pymqi/examples.html#how-to-subscribe-to-topics-and-avoid-mqrc-sub-already-exists-at-the-same-time
        self.check.log.debug('Subscribing to `%s` topic string: %s.', self.TYPE, self.TOPIC_STRING)
        METHOD_NAME.METHOD_NAME(
            sub_name=self.name,
            topic_string=self.TOPIC_STRING,
            sub_opts=(
                pymqi.CMQC.MQSO_CREATE
                + pymqi.CMQC.MQSO_RESUME
                + pymqi.CMQC.MQSO_NON_DURABLE
                + pymqi.CMQC.MQSO_MANAGED
            ),
        )
        self._sub = METHOD_NAME
    return self._sub