_________________ TestSession.test_implicit_sessions_checkout __________________

self = <test.test_session.TestSession testMethod=test_implicit_sessions_checkout>

    def test_implicit_sessions_checkout(self):
        # "To confirm that implicit sessions only allocate their server session after a
        # successful connection checkout" test from Driver Sessions Spec.
        succeeded = False
        lsid_set = set()
        failures = 0
        for _ in range(5):
            listener = OvertCommandListener()
            client = self.rs_or_single_client(event_listeners=[listener], maxPoolSize=1)
            cursor = client.db.test.find({})
            ops: List[Tuple[Callable, List[Any]]] = [
                (client.db.test.find_one, [{"_id": 1}]),
                (client.db.test.delete_one, [{}]),
                (client.db.test.update_one, [{}, {"$set": {"x": 2}}]),
                (client.db.test.bulk_write, [[UpdateOne({}, {"$set": {"x": 2}})]]),
                (client.db.test.find_one_and_delete, [{}]),
                (client.db.test.find_one_and_update, [{}, {"$set": {"x": 1}}]),
                (client.db.test.find_one_and_replace, [{}, {}]),
                (client.db.test.aggregate, [[{"$limit": 1}]]),
                (client.db.test.find, []),
                (client.server_info, []),
                (client.db.aggregate, [[{"$listLocalSessions": {}}, {"$limit": 1}]]),
                (cursor.distinct, ["_id"]),
                (client.db.list_collections, []),
            ]
            tasks = []
            listener.reset()
    
            def target(op, *args):
                if iscoroutinefunction(op):
                    res = op(*args)
                else:
                    res = op(*args)
                if isinstance(res, (Cursor, CommandCursor)):
                    res.to_list()
    
            for op, args in ops:
                tasks.append(
                    ExceptionCatchingTask(target=target, args=[op, *args], name=op.__name__)
                )
                tasks[-1].start()
            self.assertEqual(len(tasks), len(ops))
            for t in tasks:
                t.join()
                self.assertIsNone(t.exc)
            client.close()
            lsid_set.clear()
            for i in listener.started_events:
                if i.command.get("lsid"):
                    lsid_set.add(i.command.get("lsid")["id"])
            if len(lsid_set) == 1:
                succeeded = True
            else:
                failures += 1
>       self.assertTrue(succeeded, lsid_set)
E       AssertionError: False is not true : {Binary(b'C[\xf3\x04~\x8cD\xfa\x99|m\x06\xf9\xf9W\x02', 4), Binary(b'\xc1"\xd4\xda\xfd\xc1G\xca\x8dnvQ\xad\xea\xc6\xef', 4)}