docs: def submit_single(self, c_key, c_len, value, item, key_options, global_options, mres):
          """
          Submit a single item
          :param c_key: The pointer to the key
          :param c_len: The length of the key
          :param value: The value object. May be None
          :param item: The Item. May be None
          :param key_options: Key-specific options (may be None)
          :param global_options: Global options for the command
          :param mres: The MultiResult item. Used to create a cookie
          :return: A status code
          """
          raise NotImplementedError()