@Override
    protected KeyValue<Bytes, byte[]> getIndexKeyValue(final Bytes baseKey, final byte[] baseValue) {
        final byte[] key = TimeFirstWindowKeySchema.extractStoreKeyBytes(baseKey.get());
        final long timestamp = TimeFirstWindowKeySchema.extractStoreTimestamp(baseKey.get());
        final int seqnum = TimeFirstWindowKeySchema.extractStoreSequence(baseKey.get());

        return KeyValue.pair(KeyFirstWindowKeySchema.toStoreKeyBinary(key, timestamp, seqnum), new byte[0]);
    }
A RocksDB backed time-ordered segmented bytes store for window key schema.
streams/src/main/java/org/apache/kafka/streams/state/internals/RocksDBTimeOrderedWindowSegmentedBytesStore.java