code: def tearDownClass(cls) -> None:
      ray.shutdown()
  
imports: import gymnasium
  import numpy
  import tree
  import unittest
  import ray
  from ray.rllib.utils.framework import try_import_tf, try_import_torch
  from ray.rllib.utils.numpy import flatten_inputs_to_1d_tensor
  from ray.rllib.utils.numpy import make_action_immutable
  from ray.rllib.utils.test_utils import check
  from ray.rllib.utils.tf_utils import flatten_inputs_to_1d_tensor, l2_loss, one_hot
  from ray.rllib.utils.torch_utils import flatten_inputs_to_1d_tensor, l2_loss, one_hot
label_desc: Use image node_id 2 for calling the TestUtils obj's underlying member method code with example usage: obj.tearDownClass(cls) without return types