presto-orc/src/main/java/io/prestosql/orc/metadata/statistics/BooleanStatisticsBuilder.java/BooleanStatisticsBuilder/buildBooleanStatistics
class BooleanStatisticsBuilder:    private Optional<BooleanStatistics> buildBooleanStatistics()
    {
        if (nonNullValueCount == 0) {
            return Optional.empty();
        }
        return Optional.of(new BooleanStatistics(trueValueCount));
    }