docstr: Test synchronous remote calls to all actors asking for raw ObjectRefs.
docstr_tok: ["Test","synchronous","remote","calls","to","all","actors","asking","for","raw","ObjectRefs","."]
code: def test_sync_call_return_obj_refs(self):
      """Test synchronous remote calls to all actors asking for raw ObjectRefs."""
      actors = [Actor.remote(i, maybe_crash=False) for i in range(4)]
      manager = FaultTolerantActorManager(actors=actors)
  
      results = list(
          manager.foreach_actor(
              lambda w: w.call(),
              healthy_only=False,
              return_obj_refs=True,
          )
      )
  
      # We fired against all actors regardless of their status.
      # So we should get 40 results back.
      self.assertEqual(len(results), 4)
  
      for r in results:
          # Each result is an ObjectRef.
          self.assertTrue(r.ok)
          self.assertTrue(isinstance(r.get(), ray.ObjectRef))
  
      manager.clear()
  
imports: import functools
  import os
  from pathlib import Path
  import pickle
  import sys
  import time
  import unittest
  import ray
  from ray.util.state import list_actors
  from ray.rllib.utils.actor_manager import FaultAwareApply, FaultTolerantActorManager
label_desc: Use image node_id 5 for calling the TestActorManager obj's underlying member method code with example usage: obj.test_sync_call_return_obj_refs() without return types