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
executor_config_pod = k8s.V1Pod(
    metadata=k8s.V1ObjectMeta(name="my-name"),
    spec=k8s.V1PodSpec(
        containers=[
            k8s.V1Container(name="base", volume_mounts=[k8s.V1VolumeMount(name="my-vol", mount_path="/vol/")])
        ]
    ),
)
serialized_simple_dag_ground_truth = {
    "__version": 1,
    "dag": {
        "default_args": {
            "__type": "dict",
            "__var": {
                "depends_on_past": False,
                "retries": 1,
                "retry_delay": {"__type": "timedelta", "__var": 300.0},
                "max_retry_delay": {"__type": "timedelta", "__var": 600.0},
                "sla": {"__type": "timedelta", "__var": 100.0},
            },
        },
        "start_date": 1564617600.0,
        "_task_group": {
            "_group_id": None,
            "prefix_group_id": True,
            "children": {"bash_task": ("operator", "bash_task"), "custom_task": ("operator", "custom_task")},
            "tooltip": "",
            "ui_color": "CornflowerBlue",
            "ui_fgcolor": "#000",
            "upstream_group_ids": [],