presto-orc/src/main/java/io/prestosql/orc/metadata/statistics/StringStatisticsBuilder.java/StringStatisticsBuilder/buildColumnStatistics
class StringStatisticsBuilder:    @Override
    public ColumnStatistics buildColumnStatistics()
    {
        Optional<StringStatistics> stringStatistics = buildStringStatistics();
        stringStatistics.ifPresent(s -> verify(nonNullValueCount > 0));
        return new ColumnStatistics(
                nonNullValueCount,
                stringStatistics.map(s -> STRING_VALUE_BYTES_OVERHEAD + sum / nonNullValueCount).orElse(0L),
                null,
                null,
                null,
                stringStatistics.orElse(null),
                null,
                null,
                null,
                null);
    }