@Override
  public void processPartialResult(PartialAggregationResult partialResult) {
    if (!partialResult.isNull()) {
      deque.addLast(partialResult);
      this.accumulator.addIntermediate(partialResult.getPartialResult());
    }
  }
The aggregation result is calculated from all pre-aggregation results in the currently maintained
queue when calculating the COUNT, SUM, AVG and STDDEV/VARIANCE relevant functions.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/execution/aggregation/slidingwindow/SmoothQueueSlidingWindowAggregator.java