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
A TaskGroup is a collection of closely related tasks on the same DAG that should be grouped
together when the DAG is displayed graphically.
"""
from __future__ import annotations
import copy
import functools
import operator
import re
import weakref
from typing import TYPE_CHECKING, Any, Generator, Iterator, Sequence
from airflow.compat.functools import cache
from airflow.exceptions import (
    AirflowDagCycleException,
    AirflowException,
    DuplicateTaskIdFound,
    TaskAlreadyInTaskGroup,
)
from airflow.models.taskmixin import DAGNode, DependencyMixin
from airflow.serialization.enums import DagAttributeTypes
from airflow.utils.helpers import validate_group_key
from airflow.utils.setup_teardown import SetupTeardownContext
if TYPE_CHECKING:
    from sqlalchemy.orm import Session
    from airflow.models.abstractoperator import AbstractOperator
    from airflow.models.baseoperator import BaseOperator
    from airflow.models.dag import DAG
    from airflow.models.expandinput import ExpandInput
    from airflow.models.operator import Operator
    from airflow.utils.edgemodifier import EdgeModifier
class TaskGroup(DAGNode):