presto-orc/src/main/java/io/prestosql/orc/OrcWriteValidation.java/OrcWriteValidation/hashColumnStatistics
class OrcWriteValidation:        private static long hashColumnStatistics(SortedMap<OrcColumnId, ColumnStatistics> columnStatistics)
        {
            StatisticsHasher statisticsHasher = new StatisticsHasher();
            statisticsHasher.putInt(columnStatistics.size());
            for (Entry<OrcColumnId, ColumnStatistics> entry : columnStatistics.entrySet()) {
                statisticsHasher.putInt(entry.getKey().getId())
                        .putOptionalHashable(entry.getValue());
            }
            return statisticsHasher.hash();
        }