code: def get_raylet_pid():
      # TODO(edoakes): RAY_RAYLET_PID isn't properly set on Windows. This is
      # only used for fate-sharing with the raylet and we need a different
      # fate-sharing mechanism for Windows anyways.
      if sys.platform in ["win32", "cygwin"]:
          return None
      raylet_pid = int(os.environ["RAY_RAYLET_PID"])
      assert raylet_pid > 0
      logger.info("raylet pid is %s", raylet_pid)
      return raylet_pid
  
file_path: ray/python/ray/_private/process_watcher.py
imports: import asyncio
  import io
  import logging
  import sys
  import os
  from concurrent.futures import ThreadPoolExecutor
  import ray
  from ray.dashboard.consts import _PARENT_DEATH_THREASHOLD
  import ray.dashboard.consts
  import ray._private.ray_constants
  from ray._private.utils import run_background_task
  import psutil
label_desc: Use image node_id 1 for calling a global function with example usage: get_raylet_pid() and returns: raylet_pid, None