code: def test_build_task_group_with_operators():
      """Tests DAG with Tasks created with *Operators and TaskGroup created with taskgroup decorator"""
  
      from airflow.decorators import task
  
      def task_start():
          """Dummy Task which is First Task of Dag"""
          return "[Task_start]"
  
      def task_end():
          """Dummy Task which is Last Task of Dag"""
          print("[ Task_End  ]")
  
      # Creating Tasks
      @task
      def task_1(value):
          """Dummy Task1"""
          return f"[ Task1 {value} ]"
  
      @task
      def task_2(value):
          """Dummy Task2"""
          return f"[ Task2 {value} ]"
  
      @task
      def task_3(value):
          """Dummy Task3"""
          print(f"[ Task3 {value} ]")
  
      # Creating TaskGroups
      @task_group_decorator(group_id="section_1")
      def section_a(value):
          """TaskGroup for grouping related Tasks"""
          return task_3(task_2(task_1(value)))
  
      execution_date = pendulum.parse("20201109")
      with DAG(
          dag_id="example_task_group_decorator_mix",
          start_date=execution_date,
          tags=["example"],
      ) as dag:
          t_start = PythonOperator(
              task_id="task_start", python_callable=task_start, dag=dag
          )
          sec_1 = section_a(t_start.output)
          t_end = PythonOperator(
              task_id="task_end", python_callable=task_end, dag=dag
          )
          sec_1.set_downstream(t_end)
  
      # Testing Tasks in DAG
      assert set(dag.task_group.children.keys()) == {
          "section_1",
          "task_start",
          "task_end",
      }
      assert set(
          dag.task_group.children["section_1"].children.keys()
      ) == {
          "section_1.task_2",
          "section_1.task_3",
          "section_1.task_1",
      }
  
      # Testing Tasks downstream
      assert dag.task_dict["task_start"].downstream_task_ids == {
          "section_1.task_1"
      }
      assert dag.task_dict["section_1.task_3"].downstream_task_ids == {
          "task_end"
      }
  
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 15 for calling a global function with example usage: test_build_task_group_with_operators() and returns: str, str, value, str, str, value, str, task_3