private KTable<String, theDataList> globalStream() {

    // KStream of records from data-in topic using String and theDataSerde deserializers
    KStream<String, Data> trashStream = getBuilder().stream("data_in",Consumed.with(Serdes.String(), SerDes.theDataSerde));

    // Apply an aggregation operation on the original KStream records using an intermediate representation of a KStream (KGroupedStream)
    KGroupedStream<String, Data> KGS = trashStream.groupByKey();

    Materialized<String, theDataList, KeyValueStore<Bytes, byte[]>> materialized = Materialized.as("agg-stream-store");
    materialized = materialized.withValueSerde(SerDes.theDataDataListSerde);

    // Return a KTable
    return KGS.aggregate(() -> new theDataList(), (key, value, aggregate) -> {
        if (!value.getValideData())
            aggregate.getList().removeIf((t) -> t.getTimestamp() <= value.getTimestamp());
        else
            aggregate.getList().add(value);
        return aggregate;
    }, materialized);
}