code: def tearDownClass(cls):
      ray.shutdown()
  
imports: import gymnasium
  import numpy
  import os
  from pathlib import Path
  from random import choice
  import time
  import unittest
  import ray
  import ray.rllib.algorithms.dqn
  from ray.rllib.algorithms.bc import BCConfig
  import ray.rllib.algorithms.ppo
  from ray.rllib.examples.env.multi_agent import MultiAgentCartPole
  from ray.rllib.examples.parallel_evaluation_and_training import AssertEvalCallback
  from ray.rllib.utils.metrics.learner_info import LEARNER_INFO
  from ray.rllib.utils.test_utils import check, framework_iterator
label_desc: Use image node_id 2 for calling the TestAlgorithm obj's underlying member method code with example usage: obj.tearDownClass(cls) without return types