def test_delete_non_existent(self):
        d = self.save_leases()
        d.addCallback(lambda _: self.assertResult(
            b"DELETE", b"/configuration/leases/" + bytes(uuid4()),
            request_body=None, expected_code=NOT_FOUND,
            expected_result={u"description": u"Lease not found."}))

        def not_deleted(_):
            # No datasets were removed.
            self.assertItemsEqual(self.persistence_service.get().leases.keys(),
                                  [self.dataset1, self.dataset2])
        d.addCallback(not_deleted)
        return d
Test that if there is an output channel for messages, trying to send a
dataset/ETHPy150Open ClusterHQ/flocker/flocker/control/test/test_httpapi.py/LeasesTestsMixin.test_delete_non_existent--crossover with--dataset/ETHPy150Open twisted/nevow/nevow/test/test_athena.py/Transport.testSendMessageImmediately