code: def tearDownClass(cls) -> None:
      ray.shutdown()
  
file_path: ray/rllib_contrib/r2d2/tests/test_r2d2.py
imports: import unittest
  from rllib_r2d2.r2d2.r2d2 import R2D2Config
  import ray
  from ray.rllib.utils.framework import try_import_tf, try_import_torch
  from ray.rllib.utils.metrics.learner_info import LEARNER_INFO
  from ray.rllib.utils.test_utils import check_compute_single_action, check_train_results, framework_iterator
label_desc: Use image node_id 2 for calling the TestR2D2 obj's underlying member method code with example usage: obj.tearDownClass(cls) without return types