code: def test_mapped_task_group_id_prefix_task_id():
      def f(z):
          pass
  
      with DAG(dag_id="d", start_date=DEFAULT_DATE) as dag:
          x1 = dag.task(task_id="t1")(f).expand(z=[])
          with TaskGroup("g"):
              x2 = dag.task(task_id="t2")(f).expand(z=[])
  
      assert x1.operator.task_id == "t1"
      assert x2.operator.task_id == "g.t2"
  
      dag.get_task("t1") == x1.operator
      dag.get_task("g.t2") == x2.operator
  
imports: from __future__ import annotations
  from airflow.models.dag import DAG
  from airflow.utils.task_group import TaskGroup
  from tests.models import DEFAULT_DATE
label_desc: Use image node_id 1 for calling a global function with example usage: test_mapped_task_group_id_prefix_task_id() without return types