code: def pool_4_processes_python_multiprocessing_lib():
      import multiprocessing as mp
  
      pool = mp.Pool(processes=4)
      yield pool
      pool.terminate()
      pool.join()
  
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 4 for calling a global function with example usage: pool_4_processes_python_multiprocessing_lib() without return types