code: def init():
      ray.init(num_cpus=4)
      yield
      ray.shutdown()
  
file_path: ray/python/ray/tests/test_actor_pool.py
imports: import asyncio
  import sys
  import time
  from unittest.mock import MagicMock
  import pytest
  import ray
  from ray.util import ActorPool
label_desc: Use image node_id 1 for calling a global function with example usage: init() without return types