code: def record_used(kind, hash):
      
      if os.path.exists(LOG_FILEPATH):
          log = open(os.path.join(ROOT, 'used'), 'a')
      else:
          log = open(os.path.join(ROOT, 'used'), 'w+')
  
      log.writelines(["%s...%s\n" % (kind, hash)])
docs: Indicates a cachefile with the name 'hash' of a particular kind has been used so it will note be deleted on the next purge.
  
      :param str kind: The kind of cachefile. One of 'cache', 'seeds', or 'evs'
      :param str hash: The hash for the call descriptor, expected value descriptor, or counter seed.
  
      :rtype: None