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
"_is_mapped": True,
        "_task_module": "tests.test_utils.mock_operators",
        "_task_type": "MockOperator",
        "downstream_task_ids": [],
        "expand_input": {
            "type": "list-of-dicts",
            "value": {"__type": "xcomref", "__var": {"task_id": "op1", "key": "return_value"}},
        },
        "partial_kwargs": {},
        "task_id": "task_2",
        "template_fields": ["arg1", "arg2"],
        "template_ext": [],
        "template_fields_renderers": {},
        "operator_extra_links": [],
        "ui_color": "#fff",
        "ui_fgcolor": "#000",
        "_disallow_kwargs_override": strict,
        "_expand_input_attr": "expand_input",
    }
    op = SerializedBaseOperator.deserialize_operator(serialized)
    assert op.deps is MappedOperator.deps_for(BaseOperator)
    assert op._disallow_kwargs_override == strict
    # The XComArg can't be deserialized before the DAG is.
    xcom_ref = op.expand_input.value
    assert xcom_ref == _XComRef({"task_id": "op1", "key": XCOM_RETURN_KEY})
    serialized_dag: DAG = SerializedDAG.from_dict(SerializedDAG.to_dict(dag))
    xcom_arg = serialized_dag.task_dict["task_2"].expand_input.value
    assert isinstance(xcom_arg, PlainXComArg)
    assert xcom_arg.operator is serialized_dag.task_dict["op1"]
def test_operator_expand_deserialized_unmap():