code: def __init__(self):
      self.pid = None
  
imports: import asyncio
  import os
  import argparse
  import ray
  from ray._private.state_api_test_utils import verify_failed_task
  from ray.util.state import list_workers
  from ray._private.test_utils import wait_for_condition, get_ray_default_worker_file_path
  from ray.util.scheduling_strategies import PlacementGroupSchedulingStrategy
label_desc: Use image node_id 1 to create a new PidDB object  with example: obj = PidDB()