code: def _encode_message_set(cls, messages):
          
          message_set = []
          for message in messages:
              encoded_message = KafkaProtocol._encode_message(message)
              message_set.append(struct.pack('>qi%ds' % len(encoded_message), 0,
                                             len(encoded_message),
                                             encoded_message))
          return b''.join(message_set)
docs: Encode a MessageSet. Unlike other arrays in the protocol,
          MessageSets are not length-prefixed
  
          Format
          ======
          MessageSet => [Offset MessageSize Message]
            Offset => int64
            MessageSize => int32