code: def ray_start_4_cpu():
      address_info = ray.init(num_cpus=4)
      yield address_info
      # The code after the yield will run as teardown code.
      ray.shutdown()
  
imports: import os
  import sys
  import platform
  import pytest
  import tempfile
  import time
  import random
  from collections import defaultdict
  import queue
  import math
  import ray
  from ray._private.test_utils import SignalActor
  from ray.util.multiprocessing import Pool, TimeoutError, JoinableQueue
  from ray.util.joblib import register_ray
  from joblib import parallel_backend, Parallel, delayed
label_desc: Use image node_id 6 for calling a global function with example usage: ray_start_4_cpu() without return types