presto-orc/src/main/java/io/prestosql/orc/writer/StructColumnWriter.java/StructColumnWriter/getColumnStripeStatistics
class StructColumnWriter:    @Override
    public Map<OrcColumnId, ColumnStatistics> getColumnStripeStatistics()
    {
        checkState(closed);
        ImmutableMap.Builder<OrcColumnId, ColumnStatistics> columnStatistics = ImmutableMap.builder();
        columnStatistics.put(columnId, ColumnStatistics.mergeColumnStatistics(rowGroupColumnStatistics));
        structFields.stream()
                .map(ColumnWriter::getColumnStripeStatistics)
                .forEach(columnStatistics::putAll);
        return columnStatistics.build();
    }