code: def is_not_blocked(self, item: str) -> bool:
          
          assert item is not None
          item = self._encode_item(item)
          connection = self.__get_connection()
          key = self.__redis_conf['blacklist_template'].format(item)
          value = connection.get(key)
          if value is None:
              BlackRed.__release_connection(connection)
              return True
          if self.__redis_conf['blacklist_refresh_ttl']:
              connection.expire(key, self.__redis_conf['blacklist_ttl'])
          BlackRed.__release_connection(connection)
          return False
docs: Check if an item is _not_ already on the blacklist
  
          :param str item: The item to check
          :return: True, when the item is _not_ on the blacklist
          :rtype: bool