presto-orc/src/main/java/io/prestosql/orc/writer/SliceDirectColumnWriter.java/SliceDirectColumnWriter/reset
class SliceDirectColumnWriter:    @Override
    public void reset()
    {
        checkState(closed);
        closed = false;
        lengthStream.reset();
        dataStream.reset();
        presentStream.reset();
        rowGroupColumnStatistics.clear();
        statisticsBuilder = statisticsBuilderSupplier.get();
    }