public boolean isOutputEndTime() {
    return outputEndTime;
  }
This node is used to aggregate required series from multiple sources. The source data will be
input as a TsBlock, it may be raw data or partial aggregation result. This node will output the
final series aggregated result represented by TsBlock.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/planner/plan/node/process/AggregationNode.java