code: def test_skip_plasma(ray_start_regular_shared):
      @ray.remote
      class Actor:
          def __init__(self):
              pass
  
          def f(self, x):
              return x * 2
  
      a = Actor.remote()
      obj_ref = a.f.remote(1)
      # it is not stored in plasma
      assert not ray._private.worker.global_worker.core_worker.object_exists(
          obj_ref
      )
      assert ray.get(obj_ref) == 2
  
imports: import array
  import logging
  import os
  import random
  import subprocess
  import sys
  import tempfile
  import threading
  import time
  from unittest.mock import MagicMock, patch
  import pytest
  from ray._private.ray_constants import KV_NAMESPACE_FUNCTION_TABLE
  from ray._private.test_utils import client_test_enabled
  from ray.cluster_utils import Cluster, cluster_not_supported
  from ray.exceptions import GetTimeoutError, RayTaskError
  from ray.tests.client_test_utils import create_remote_signal_actor
label_desc: Use image node_id 13 for calling a global function with example usage: test_skip_plasma(ray_start_regular_shared) and returns: unknown