presto-orc/src/main/java/io/prestosql/orc/writer/FloatColumnWriter.java/FloatColumnWriter/finishRowGroup
class FloatColumnWriter:    @Override
    public Map<OrcColumnId, ColumnStatistics> finishRowGroup()
    {
        checkState(!closed);
        ColumnStatistics statistics = statisticsBuilder.buildColumnStatistics();
        rowGroupColumnStatistics.add(statistics);
        statisticsBuilder = new DoubleStatisticsBuilder();
        return ImmutableMap.of(columnId, statistics);
    }