@Override
  protected void serialize(ByteBuffer byteBuffer) {
    ReadWriteIOUtils.write(startTime, byteBuffer);
    ReadWriteIOUtils.write(endTime, byteBuffer);
    interval.serialize(byteBuffer);
    slidingStep.serialize(byteBuffer);
  }
Only used for representing GROUP BY TIME filter.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/expression/other/GroupByTimeExpression.java