basic-lib/src/main/java/com/streamsets/pipeline/stage/processor/aggregation/aggregator/Aggregators.java
public Map<Aggregator, AggregatorData> stop() {
    Utils.checkState(started, "Already started");
    Utils.checkState(!stopped, "Already stopped");
    Map<Aggregator, AggregatorData> aggregatorDataMap = dataProvider.stop();
    stopped = true;
    return aggregatorDataMap;
  }
public Map<Aggregator, AggregatorData> stop() {
    Utils.checkState(started, "Already started");
    Utils.checkState(!stopped, "Already stopped");
    Map<Aggregator, AggregatorData> aggregatorDataMap = dataProvider.stop();
    stopped = true;
    return aggregatorDataMap;
  }
Stops the Aggregators instance.