code: def url_ok(match_tuple: MatchTuple) -> Tuple[bool, str]:
      """Check if a URL is reachable."""
      try:
          result = http_session.head(
              match_tuple.link, timeout=5, allow_redirects=True
          )
          return (
              result.ok or result.status_code in OK_STATUS_CODES,
              f"status code = {result.status_code}",
          )
      except (requests.ConnectionError, requests.Timeout):
          return False, "connection error"
  
file_path: allennlp/scripts/check_links.py
imports: import re
  import sys
  import pathlib
  import os
  from multiprocessing.dummy import Pool
  from typing import Tuple, NamedTuple, Optional
  import requests
label_desc: Use image node_id 1 for calling a global function with example usage: url_ok(match_tuple) and returns: unknown,  str, result, False,  str