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
def __init__(self, do_xcom_push=False, **kwargs):
                super().__init__(**kwargs)
                self.do_xcom_push = do_xcom_push
        op = MyOperator(task_id="dummy")
        assert op.do_xcom_push is False
        blob = SerializedBaseOperator.serialize_operator(op)
        serialized_op = SerializedBaseOperator.deserialize_operator(blob)
        assert serialized_op.do_xcom_push is False
    def test_no_new_fields_added_to_base_operator(self):