code: def test_reducer_override_no_reference_cycle(
      ray_start_shared_local_modes,
  ):
      # bpo-39492: reducer_override used to induce a spurious reference cycle
      # inside the Pickler object, that could prevent all serialized objects
      # from being garbage-collected without explicity invoking gc.collect.
  
      # test a dynamic function
      def f():
          return 4669201609102990671853203821578
  
      wr = weakref.ref(f)
  
      bio = io.BytesIO()
      from ray.cloudpickle import CloudPickler, dumps, loads
  
      p = CloudPickler(bio, protocol=5)
      p.dump(f)
      new_f = loads(bio.getvalue())
      assert new_f() == 4669201609102990671853203821578
  
      del p
      del f
  
      assert wr() is None
  
      # test a dynamic class
      class ShortlivedObject:
          def __del__(self):
              print("Went out of scope!")
  
      obj = ShortlivedObject()
      new_obj = weakref.ref(obj)
  
      dumps(obj)
      del obj
      assert new_obj() is None
  
imports: import collections
  import io
  import logging
  import re
  import string
  import sys
  import weakref
  from dataclasses import make_dataclass
  import numpy
  import pytest
  from numpy import log
  import ray
  import ray.cluster_utils
label_desc: Use image node_id 10 for calling a global function with example usage: test_reducer_override_no_reference_cycle(ray_start_shared_local_modes) and returns: int