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
"""Get a child task/TaskGroup by its label (i.e. task_id/group_id without the group_id prefix)"""
        return self.children[self.child_id(label)]
    def serialize_for_task_group(self) -> tuple[DagAttributeTypes, Any]:
        """Required by DAGNode."""
        from airflow.serialization.serialized_objects import TaskGroupSerialization
        return DagAttributeTypes.TASK_GROUP, TaskGroupSerialization.serialize_task_group(self)
    def topological_sort(self, _include_subdag_tasks: bool = False):
        """
        Sorts children in topographical order, such that a task comes after any of its
        upstream dependencies.
        :return: list of tasks in topological order
        """
        
        
        from airflow.operators.subdag import SubDagOperator  
        graph_unsorted = copy.copy(self.children)
        graph_sorted: list[DAGNode] = []
        
        if len(self.children) == 0:
            return graph_sorted
        
        while graph_unsorted: