code: def tearDownClass(cls):
      ray.shutdown()
  
file_path: ray/rllib/evaluation/tests/test_worker_set.py
imports: import gymnasium
  import unittest
  import ray
  from ray.rllib.algorithms.algorithm_config import AlgorithmConfig
  from ray.rllib.evaluation.worker_set import WorkerSet
  from ray.rllib.examples.policy.random_policy import RandomPolicy
  from ray.rllib.policy.sample_batch import DEFAULT_POLICY_ID
label_desc: Use image node_id 2 for calling the TestWorkerSet obj's underlying member method code with example usage: obj.tearDownClass(cls) without return types