code: def tearDownClass(cls) -> None:
      ray.shutdown()
  
file_path: ray/python/ray/rllib/evaluation/tests/test_postprocessing.py
imports: import numpy
  import unittest
  import ray
  from ray.rllib.evaluation.postprocessing import adjust_nstep, discount_cumsum
  from ray.rllib.policy.sample_batch import SampleBatch
  from ray.rllib.utils.test_utils import check
label_desc: Use image node_id 2 for calling the TestPostprocessing obj's underlying member method code with example usage: obj.tearDownClass(cls) without return types