Ensure that this works:

```python
@setup
def mytask():
    print("I am a setup task")

with dag_maker() as dag:
    mytask.override(task_id='newtask')

assert len(dag.task_group.children) == 1
setup_task = dag.task_group.children["newtask"]
assert setup_task._is_setup
```
and teardown also works
BaseHook.get_connection = self.backup_base_hook_get_connection
    def test_serialization(self):
        """Serialization and deserialization should work for every DAG and Operator."""
        dags = collect_dags()
        serialized_dags = {}
        for _, v in dags.items():
            dag = SerializedDAG.to_dict(v)
            SerializedDAG.validate_schema(dag)
            serialized_dags[v.dag_id] = dag
        
        self.validate_serialized_dag(serialized_dags["simple_dag"], serialized_simple_dag_ground_truth)
    @pytest.mark.parametrize(
        "timetable, serialized_timetable",
        [
            (
                cron_timetable("0 0 * * *"),
                {
                    "__type": "airflow.timetables.interval.CronDataIntervalTimetable",
                    "__var": {"expression": "0 0 * * *", "timezone": "UTC"},
                },
            ),
            (
                CustomSerializationTimetable("foo"),
                CUSTOM_TIMETABLE_SERIALIZED,
            ),
        ],
    )
    @pytest.mark.usefixtures("timetable_plugin")
    def test_dag_serialization_to_timetable(self, timetable, serialized_timetable):