code: def thread_init(q: Queue, user_init: UserInit, loglevel) -> None:
      """Begin a thread pool worker."""
      del q  # unused but required argument
      del loglevel  # unused but required argument
      # As a thread, block SIGBUS so the main thread deals with it...
      with suppress(AttributeError):
          signal.pthread_sigmask(signal.SIG_BLOCK, {signal.SIGBUS})
  
      user_init()
      return
  
imports: from __future__ import annotations
  import logging
  import logging.handlers
  import multiprocessing
  import os
  import queue
  import signal
  import sys
  import threading
  from collections.abc import Iterable
  from concurrent.futures import ProcessPoolExecutor, ThreadPoolExecutor, as_completed
  from contextlib import suppress
  from typing import Callable, Union
  from rich.console import Console
  from ocrmypdf import Executor, hookimpl
  from ocrmypdf._logging import RichLoggingHandler
  from ocrmypdf._progressbar import RichProgressBar
  from ocrmypdf.exceptions import InputFileError
  from ocrmypdf.helpers import remove_all_log_handlers
label_desc: Use image node_id 4 for calling a global function with example usage: thread_init(q, user_init, loglevel) without return types