@Override
  public synchronized void close() {
    super.close();

    if (tabletBatchBuilder != null) {
      tabletBatchBuilder.close();
    }
  }
This connector is used for PipeConsensus to transfer queued event.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/pipe/connector/protocol/pipeconsensus/PipeConsensusSyncConnector.java