public void serialize(final OutputStream outputStream) throws IOException {
    ReadWriteIOUtils.write(topicName, outputStream);
    ReadWriteIOUtils.write(creationTime, outputStream);

    ReadWriteIOUtils.write(config.getAttribute().size(), outputStream);
    for (final Map.Entry<String, String> entry : config.getAttribute().entrySet()) {
      ReadWriteIOUtils.write(entry.getKey(), outputStream);
      ReadWriteIOUtils.write(entry.getValue(), outputStream);
    }

    ReadWriteIOUtils.write(subscribedConsumerGroupIds.size(), outputStream);
    for (final String subscribedConsumerGroupID : subscribedConsumerGroupIds) {
      ReadWriteIOUtils.write(subscribedConsumerGroupID, outputStream);
    }
  }
@return true if the consumer group did not already subscribe this topic
iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/subscription/meta/topic/TopicMeta.java