def _unbind_router(self, context, router_id, agent_id):
        with context.session.begin(subtransactions=True):
            query = context.session.query(RouterL3AgentBinding)
            query = query.filter(
                RouterL3AgentBinding.router_id == router_id,
                RouterL3AgentBinding.l3_agent_id == agent_id)
            query.delete()
dataset/ETHPy150Open openstack/neutron/neutron/db/l3_agentschedulers_db.py/L3AgentSchedulerDbMixin._unbind_router/original