docs: def mint_sub(client_salt, sector_id="", subject_type="public",
               uid='', user_salt=''):
      """
      Mint a new sub (subject identifier)
  
      :param authn_event: Authentication event information
      :param client_salt: client specific salt - used in pairwise
      :param sector_id: Possible sector identifier
      :param subject_type: 'public'/'pairwise'
      :return: Subject identifier
      """
  
      if subject_type == "public":
          sub = hashlib.sha256(
              "{}{}".format(uid, user_salt).encode("utf-8")).hexdigest()
      else:
          sub = pairwise_id(uid, sector_id,
                            "{}{}".format(client_salt, user_salt))
      return sub