code: def task_id() -> Optional[int]:
      """Returns the current task id, if any.
  
      Returns None if this process was not created by `fork_processes`.
      """
      global _task_id
      return _task_id
  
imports: import asyncio
  import os
  import multiprocessing
  import signal
  import subprocess
  import sys
  import time
  from binascii import hexlify
  from tornado.concurrent import Future, future_set_result_unless_cancelled, future_set_exception_unless_cancelled
  from tornado import ioloop
  from tornado.iostream import PipeIOStream
  from tornado.log import gen_log
  import typing
  from typing import Optional, Any, Callable
label_desc: Use image node_id 4 for calling a global function with example usage: task_id() and returns: _task_id