public synchronized void clearValues(long startTimeOfNewAggregates, StreamEvent resetEvent) {
        this.initialTimestamp = startTimeOfNewAggregates;
        setTimestamp(startTimeOfNewAggregates);
        setProcessed(false);
        this.valueStateHolder.cleanGroupByStates();
    }
Store for maintaining the base values related to incremental aggregation. (e.g. for average,
the base incremental values would be sum and count. The timestamp too is stored here.
modules/siddhi-core/src/main/java/io/siddhi/core/aggregation/BaseIncrementalValueStore.java