code: def tearDown(self) -> None:
      ray.shutdown()
  
file_path: ray/rllib/tests/test_placement_groups.py
imports: import os
  import unittest
  import ray
  from ray import air
  from ray import tune
  from ray.tune import Callback
  from ray.rllib.algorithms.ppo import PPO, PPOConfig
  from ray.tune.experiment import Trial
  from ray.tune.execution.placement_groups import PlacementGroupFactory
label_desc: Use image node_id 2 for calling the TestPlacementGroups obj's underlying member method code with example usage: obj.tearDown() without return types