code: def test_object_unpin_stress(ray_start_cluster):
      nodes = []
      cluster = ray_start_cluster
      cluster.add_node(
          num_cpus=1,
          resources={"head": 1},
          object_store_memory=1000 * 1024 * 1024,
      )
      ray.init(address=cluster.address)
  
      # Add worker nodes.
      for i in range(2):
          nodes.append(
              cluster.add_node(
                  num_cpus=1,
                  resources={f"node_{i}": 1},
                  object_store_memory=1000 * 1024 * 1024,
              )
          )
      cluster.wait_for_nodes()
  
      one_mb_array = np.ones(1 * 1024 * 1024, dtype=np.uint8)
      ten_mb_array = np.ones(10 * 1024 * 1024, dtype=np.uint8)
  
      @ray.remote
      class ObjectsHolder:
          def __init__(self):
              self.ten_mb_objs = []
              self.one_mb_objs = []
  
          def put_10_mb(self):
              self.ten_mb_objs.append(ray.put(ten_mb_array))
  
          def put_1_mb(self):
              self.one_mb_objs.append(ray.put(one_mb_array))
  
          def pop_10_mb(self):
              if len(self.ten_mb_objs) == 0:
                  return False
              self.ten_mb_objs.pop()
              return True
  
          def pop_1_mb(self):
              if len(self.one_mb_objs) == 0:
                  return False
              self.one_mb_objs.pop()
              return True
  
          def get_obj_size(self):
              return len(self.ten_mb_objs) * 10 + len(self.one_mb_objs)
  
      actor_on_node_1 = ObjectsHolder.options(
          resources={"node_0": 1}
      ).remote()
      actor_on_node_2 = ObjectsHolder.options(
          resources={"node_1": 1}
      ).remote()
      actor_on_head_node = ObjectsHolder.options(
          resources={"head": 1}
      ).remote()
  
      ray.get(actor_on_node_1.get_obj_size.remote())
      ray.get(actor_on_node_2.get_obj_size.remote())
      ray.get(actor_on_head_node.get_obj_size.remote())
  
      def random_ops(actors):
          r = random.random()
          for actor in actors:
              if r <= 0.25:
                  actor.put_10_mb.remote()
              elif r <= 0.5:
                  actor.put_1_mb.remote()
              elif r <= 0.75:
                  actor.pop_10_mb.remote()
              else:
                  actor.pop_1_mb.remote()
  
      total_iter = 15
      for _ in range(total_iter):
          random_ops(
              [actor_on_node_1, actor_on_node_2, actor_on_head_node]
          )
  
      # Simulate node dead.
      cluster.remove_node(nodes[1])
      for _ in range(total_iter):
          random_ops([actor_on_node_1, actor_on_head_node])
  
      total_size = sum(
          [
              ray.get(actor_on_node_1.get_obj_size.remote()),
              ray.get(actor_on_head_node.get_obj_size.remote()),
          ]
      )
  
      wait_for_condition(
          lambda: (
              (f"Plasma memory usage {total_size} MiB")
              in memory_summary(stats_only=True)
          )
      )
  
imports: import logging
  import os
  import copy
  import platform
  import random
  import signal
  import sys
  import time
  import numpy
  import pytest
  import ray
  import ray.cluster_utils
  from ray._private.internal_api import memory_summary
  from ray._private.test_utils import SignalActor, put_object, wait_for_condition, wait_for_num_actors
  import ray._private.gcs_utils
label_desc: Use image node_id 10 for calling a global function with example usage: test_object_unpin_stress(ray_start_cluster) and returns: True, True, unknown, False, False