code: def get_executor(progressbar_class: type[ProgressBar]) -> Executor:
      """Called to obtain an object that manages parallel execution.
  
      This may be used to replace OCRmyPDF's default parallel execution system
      with a third party alternative. For example, you could make OCRmyPDF run in a
      distributed environment.
  
      OCRmyPDF's executors are analogous to the standard Python executors in
      ``conconcurrent.futures``, but they do not work the same way. Executors may
      be reused for different, unrelated batch operations, since all of the context
      for a given job are passed to :meth:`Executor.__call__`.
  
      Should be of type :class:`Executor` or otherwise conforming to the protocol
      of that call.
  
      Arguments:
          progressbar_class: A progress bar class, which will be created when
  
      Note:
          This hook will be called from the main process, and may modify global state
          before child worker processes are forked.
  
      Note:
          This is a :ref:`firstresult hook<firstresult>`.
      """
  
imports: from __future__ import annotations
  from abc import ABC, abstractmethod
  from argparse import ArgumentParser, Namespace
  from collections.abc import Sequence, Set
  from logging import Handler
  from pathlib import Path
  from typing import TYPE_CHECKING, NamedTuple
  import pluggy
  from ocrmypdf import Executor, PdfContext
  from ocrmypdf._progressbar import ProgressBar
  from ocrmypdf.helpers import Resolution
label_desc: Use image node_id 5 for calling a global function with example usage: get_executor(progressbar_class) without return types