code: def init_requests_cache(refresh_cache=False):
      
      # Cache data from external sources; used in some checks
      dirs = AppDirs("stix2-validator", "OASIS")
      # Create cache dir if doesn't exist
      try:
          os.makedirs(dirs.user_cache_dir)
      except OSError as e:
          if e.errno != errno.EEXIST:
              raise
      requests_cache.install_cache(
          cache_name=os.path.join(dirs.user_cache_dir, 'py{}cache'.format(
              sys.version_info[0])),
          expire_after=datetime.timedelta(weeks=1))
  
      if refresh_cache:
          clear_requests_cache()
docs: Initializes a cache which the ``requests`` library will consult for
      responses, before making network requests.
  
      :param refresh_cache: Whether the cache should be cleared out