code: public static Message buildSyncHistoryReply(int timeout) {
      ZabMessage.SyncHistoryReply reply =
        ZabMessage.SyncHistoryReply.newBuilder().setSyncTimeout(timeout).build();
      return Message.newBuilder().setType(MessageType.SYNC_HISTORY_REPLY)
                                 .setSyncHistoryReply(reply).build();
    }
docs: Creates the SYNC_HISTORY_REPLY message. It's the first time to tell the
  joiner the synchronization timeout.
  
  @param timeout timeout in milliseconds.
  @return a protobuf message.