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
self,
        serialized_timetable,
        expected_timetable,
    ):
        serialized = {
            "__version": 1,
            "dag": {
                "default_args": {"__type": "dict", "__var": {}},
                "_dag_id": "simple_dag",
                "fileloc": __file__,
                "tasks": [],
                "timezone": "UTC",
                "timetable": serialized_timetable,
            },
        }
        SerializedDAG.validate_schema(serialized)
        dag = SerializedDAG.from_dict(serialized)
        assert dag.timetable == expected_timetable
    def test_deserialization_timetable_unregistered(self):
        serialized = {
            "__version": 1,
            "dag": {
                "default_args": {"__type": "dict", "__var": {}},
                "_dag_id": "simple_dag",
                "fileloc": __file__,