class_docstr: A class the contains a naive implementation for concurrent sub-process
  execution. It uses `subprocess.Popen` and threads to read from stdout and
  stderr of the subprocess, and to write to stdin of the subprocess.
  
  All read data and timeouts are passed to a protocol instance, which can
  create the final result.
class_docstr_tok: ["A","class","the","contains","a","naive","implementation","for","concurrent","sub-process","execution",".","It","uses","`","subprocess.Popen","`","and","threads","to","read","from","stdout","and","stderr","of","the","subprocess",",","and","to","write","to","stdin","of","the","subprocess",".","All","read","data","and","timeouts","are","passed","to","a","protocol","instance",",","which","can","create","the","final","result","."]
code: def remove_process(self):
      if None not in self.active_file_numbers:
          # Might already be removed due to a timeout callback returning
          # True and subsequent removal of the process.
          return
      self.active_file_numbers.remove(None)
      if self.timeout:
          del self.last_touched[None]
  
      # Remove stdin from the active set because the process will
      # no longer consume input from stdin. This is done by enqueuing
      # None to the stdin queue.
      if self.write_stdin:
          self.stdin_queue.put(None)
  
      self.return_code = self.process.poll()
  
imports: from __future__ import annotations
  import enum
  import logging
  import subprocess
  import threading
  import time
  from collections import deque
  from collections.abc import Generator
  from queue import Empty, Queue
  from subprocess import Popen
  from typing import IO, Any, Optional
  from datalad.utils import on_windows
  from .exception import CommandError
  from .protocol import GeneratorMixIn, WitlessProtocol
  from .runnerthreads import IOState, ReadThread, WaitThread, WriteThread, _try_close
label_desc: Use image node_id 16 for calling the ThreadedRunner obj's underlying member method code with example usage: obj.remove_process() without return types