presto-hive/src/main/java/io/prestosql/plugin/hive/metastore/thrift/ThriftHiveMetastore.java/ThriftHiveMetastore/groupStatisticsByColumn
class ThriftHiveMetastore:    private Map<String, HiveColumnStatistics> groupStatisticsByColumn(List<ColumnStatisticsObj> statistics, OptionalLong rowCount)
    {
        return statistics.stream()
                .collect(toImmutableMap(ColumnStatisticsObj::getColName, statisticsObj -> ThriftMetastoreUtil.fromMetastoreApiColumnStatistics(statisticsObj, rowCount)));
    }