private void processAggregates(StreamEvent streamEvent, ExecutorState executorState) {
        synchronized (this) {
            if (groupByKeyGenerator != null) {
                try {
                    String groupedByKey = groupByKeyGenerator.constructEventKey(streamEvent);
                    SiddhiAppContext.startGroupByFlow(groupedByKey);
                    baseIncrementalValueStore.process(streamEvent);
                } finally {
                    SiddhiAppContext.stopGroupByFlow();
                }
            } else {
                baseIncrementalValueStore.process(streamEvent);
            }
        }
    }
Incremental executor class which is responsible for performing incremental aggregation.
modules/siddhi-core/src/main/java/io/siddhi/core/aggregation/IncrementalExecutor.java