code: def test_hierarchical_alphabetical_sort():
      execution_date = pendulum.parse("20200101")
      with DAG("test_dag_edges", start_date=execution_date) as dag:
          task1 = EmptyOperator(task_id="task1")
          task5 = EmptyOperator(task_id="task5")
          with TaskGroup("group_c"):
              task7 = EmptyOperator(task_id="task7")
          with TaskGroup("group_b"):
              task6 = EmptyOperator(task_id="task6")
          with TaskGroup("group_a"):
              with TaskGroup("group_d"):
                  task2 = EmptyOperator(task_id="task2")
                  task3 = EmptyOperator(task_id="task3")
                  task4 = EmptyOperator(task_id="task4")
              task9 = EmptyOperator(task_id="task9")
              task8 = EmptyOperator(task_id="task8")
  
      def nested(group):
          return [
              nested(node) if isinstance(node, TaskGroup) else node
              for node in group.hierarchical_alphabetical_sort()
          ]
  
      sorted_list = nested(dag.task_group)
  
      assert sorted_list == [
          [  # group_a
              [  # group_d
                  task2,
                  task3,
                  task4,
              ],
              task8,
              task9,
          ],
          [task6],  # group_b
          [task7],  # group_c
          task1,
          task5,
      ]
  
imports: from __future__ import annotations
  from datetime import timedelta
  import pendulum
  import pytest
  from airflow.decorators import dag, setup, task, task_group, teardown
  from airflow.exceptions import TaskAlreadyInTaskGroup
  from airflow.models.baseoperator import BaseOperator
  from airflow.models.dag import DAG
  from airflow.models.xcom_arg import XComArg
  from airflow.operators.bash import BashOperator
  from airflow.operators.empty import EmptyOperator
  from airflow.operators.python import PythonOperator
  from airflow.utils.dag_edges import dag_edges
  from airflow.utils.task_group import TaskGroup, task_group_to_dict
  from tests.models import DEFAULT_DATE
label_desc: Use image node_id 26 for calling a global function with example usage: test_hierarchical_alphabetical_sort() and returns: unknown