code: def __init__(self, num_objects):
      self.barrier = threading.Barrier(num_objects, timeout=30)
  
imports: import sys
  import threading
  import pytest
  import ray
  from ray.tests.test_memory_pressure import allocate_memory, Leaker, get_additional_bytes_to_reach_memory_usage_pct, memory_usage_threshold, memory_monitor_refresh_ms
label_desc: Use image node_id 1 to create a new BarrierActor object  with example: obj = BarrierActor(num_objects)