code: def setup_class(cls):
      cls.dagbag = models.DagBag(include_examples=True)
      cls.parser = cli_parser.get_parser()
  
imports: from __future__ import annotations
  import os
  from contextlib import redirect_stdout
  from io import StringIO
  import pytest
  from sqlalchemy import select
  from airflow import models
  from airflow.cli import cli_parser
  from airflow.cli.commands import variable_command
  from airflow.models import Variable
  from airflow.utils.session import create_session
  from tests.test_utils.db import clear_db_variables
label_desc: Use image node_id 1 for calling the TestCliVariables obj's underlying member method code with example usage: obj.setup_class(cls) without return types