def lookup(self):
        farmer = Farmer.query.filter_by(btc_addr=self.btc_addr).first()
        if not farmer:
            msg = "Address not registered: {0}".format(self.btc_addr)
            logger.warning(msg)
            raise LookupError(msg)
        return farmer
Requests the task scheduler to shutdown.
dataset/ETHPy150Open Storj/dataserv/dataserv/Farmer.py/Farmer.lookup--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/api/taskqueue/taskqueue_stub.py/TaskQueueServiceStub.Shutdown