presto-spi/src/main/java/io/prestosql/spi/function/ValueWindowFunction.java/ValueWindowFunction/processRow
class ValueWindowFunction:    @Override
    public final void processRow(BlockBuilder output, int peerGroupStart, int peerGroupEnd, int frameStart, int frameEnd)
    {
        processRow(output, frameStart, frameEnd, currentPosition);

        currentPosition++;
    }