code: def test_actor_namespace(ray_start_regular_shared):
      @ray.remote
      class Actor:
          def f(self):
              return "ok"
  
      a = Actor.options(name="foo", namespace="f1").remote()
  
      with pytest.raises(ValueError):
          ray.get_actor(name="foo", namespace="f2")
  
      a1 = ray.get_actor(name="foo", namespace="f1")
      assert ray.get(a1.f.remote()) == "ok"
      del a
  
imports: import datetime
  import os
  import random
  import sys
  import tempfile
  import numpy
  import pytest
  import ray
  from ray import cloudpickle
  from ray._private import ray_constants
  from ray._private.test_utils import client_test_enabled, wait_for_condition, wait_for_pid_to_exit
  from ray.actor import ActorClassInheritanceException
  from ray.tests.client_test_utils import create_remote_signal_actor
  from ray._private.test_utils import SignalActor
  import setproctitle
label_desc: Use image node_id 35 for calling a global function with example usage: test_actor_namespace(ray_start_regular_shared) and returns: str