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
"""
        Tests serialize_task_group, make sure the list is in order
        """
        from airflow.operators.empty import EmptyOperator
        from airflow.serialization.serialized_objects import TaskGroupSerialization
        """
                    start
                    ╱  ╲
                  ╱      ╲
        task_group_up1  task_group_up2
            (task_up1)  (task_up2)
                 ╲       ╱
              task_group_middle
                (task_middle)
                  ╱      ╲
        task_group_down1 task_group_down2
           (task_down1) (task_down2)
                 ╲        ╱
                   ╲    ╱
                    end
        """
        execution_date = datetime(2020, 1, 1)
        with DAG(dag_id="test_task_group_sorted", start_date=execution_date) as dag:
            start = EmptyOperator(task_id="start")
            with TaskGroup("task_group_up1") as task_group_up1:
                _ = EmptyOperator(task_id="task_up1")
            with TaskGroup("task_group_up2") as task_group_up2:
                _ = EmptyOperator(task_id="task_up2")