code: def test_pop_idle(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()]
      pool = ActorPool(actors)
  
      pool.submit(lambda a, v: a.double.remote(v), 1)
      assert pool.pop_idle() is None
      assert pool.has_free() is False  # actor is busy
      assert pool.get_next() == 2
      assert pool.has_free()
      pool.pop_idle()  # removes actor from pool
      assert pool.has_free() is False
  
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 11 for calling a global function with example usage: test_pop_idle(init) and returns: unknown, unknown