code: def __init__(self):
      pass
  
file_path: ray/release/nightly_tests/stress_tests/test_placement_group.py
imports: import time
  from time import perf_counter
  from random import random
  import json
  import logging
  import os
  import ray
  from ray.util.placement_group import placement_group, remove_placement_group
  from ray.util.scheduling_strategies import PlacementGroupSchedulingStrategy
label_desc: Use image node_id 1 to create a new MockActor object  with example: obj = MockActor()