code: def test_map(init):
      @ray.remote
      class MyActor:
          def __init__(self):
              pass
  
          def f(self, x):
              return x + 1
  
          def double(self, x):
              return 2 * x
  
      actors = [MyActor.remote() for _ in range(4)]
      pool = ActorPool(actors)
  
      index = 0
      for v in pool.map(lambda a, v: a.double.remote(v), range(5)):
          assert v == 2 * index
          index += 1
  
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 4 for calling a global function with example usage: test_map(init) and returns: unknown, unknown