def _get_expire(self, queue, argument):
        """Gets expiration header named `argument` of queue definition.
        `queue` must be either queue name or options itself."""
        if isinstance(queue, basestring):
            doc = self.queues.find_one({'_id': queue})

            if not doc:
                return

            data = doc['options']
        else:
            data = queue

        try:
            value = data['arguments'][argument]
        except (KeyError, __HOLE__):
            return

        return self.get_now() + datetime.timedelta(milliseconds=value)
dataset/ETHPy150Open celery/kombu/kombu/transport/mongodb.py/Channel._get_expire