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
if isinstance(inlets, list)
                else [
                    inlets,
                ]
            )
        if outlets:
            self.outlets = (
                outlets
                if isinstance(outlets, list)
                else [
                    outlets,
                ]
            )
        if isinstance(self.template_fields, str):
            warnings.warn(
                f"The `template_fields` value for {self.task_type} is a string "
                "but should be a list or tuple of string. Wrapping it in a list for execution. "
                f"Please update {self.task_type} accordingly.",
                UserWarning,
                stacklevel=2,
            )
            self.template_fields = [self.template_fields]
        if SetupTeardownContext.is_setup:
            self._is_setup = True
        elif SetupTeardownContext.is_teardown:
            self._is_teardown = True
            if SetupTeardownContext.on_failure_fail_dagrun:
                self._on_failure_fail_dagrun = True
    @classmethod
    def as_setup(cls, *args, **kwargs):