presto-orc/src/main/java/io/prestosql/orc/metadata/OrcMetadataReader.java/OrcMetadataReader/toColumnStatistics
class OrcMetadataReader:    private static Optional<ColumnMetadata<ColumnStatistics>> toColumnStatistics(HiveWriterVersion hiveWriterVersion, List<OrcProto.ColumnStatistics> columnStatistics, boolean isRowGroup)
    {
        if (columnStatistics == null || columnStatistics.isEmpty()) {
            return Optional.empty();
        }
        return Optional.of(new ColumnMetadata<>(columnStatistics.stream()
                .map(statistics -> toColumnStatistics(hiveWriterVersion, statistics, isRowGroup))
                .collect(toImmutableList())));
    }