private boolean shouldUpdate(Object data, ValueState state) {
        long timestamp = (long) data;
        if (timestamp >= state.lastTimestamp) {
            state.lastTimestamp = timestamp;
            return true;
        }
        return false;
    }
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