def _take_down_agent(self):
        with self.context.session.begin(subtransactions=True):
            query = self.context.session.query(agents_db.Agent)
            agt = query.first()
            agt.heartbeat_timestamp = (
                agt.heartbeat_timestamp - datetime.timedelta(hours=1))
dataset/ETHPy150Open openstack/neutron/neutron/tests/unit/db/test_agents_db.py/TestAgentExtRpcCallback._take_down_agent/original