Custom setting allowing switch between rabbitmq, redis

def BROKER_TYPE(self):
        """Custom setting allowing switch between rabbitmq, redis"""

        broker_type = get('BROKER_TYPE', DEFAULT_BROKER_TYPE)
        if broker_type not in SUPPORTED_BROKER_TYPES:
            log.warn("Specified BROKER_TYPE {} not supported. Backing to default {}".format(
                broker_type, DEFAULT_BROKER_TYPE))
            return DEFAULT_BROKER_TYPE
        else:
            return broker_type