code: def persist(self, key, value):
          
          encoded = self.encoding.encode(value)
          self.__set_or_create(key, encoded)
          self.__increment_last_updated()
docs: Encode and save ``value`` at ``key``.
  
          :param key: Key to store ``value`` at in Zookeeper.
          :type key: string
          :param value: Value to store. Encoded before being stored.
          :type value: value