presto-orc/src/main/java/io/prestosql/orc/metadata/OrcMetadataReader.java/OrcMetadataReader/toRowGroupIndex
class OrcMetadataReader:    private static RowGroupIndex toRowGroupIndex(HiveWriterVersion hiveWriterVersion, RowIndexEntry rowIndexEntry)
    {
        List<Long> positionsList = rowIndexEntry.getPositionsList();
        ImmutableList.Builder<Integer> positions = ImmutableList.builder();
        for (int index = 0; index < positionsList.size(); index++) {
            long longPosition = positionsList.get(index);

            @SuppressWarnings("NumericCastThatLosesPrecision")
            int intPosition = (int) longPosition;
            checkArgument(intPosition == longPosition, "Expected checkpoint position [%s] value [%s] to be an integer", index, longPosition);

            positions.add(intPosition);
        }
        return new RowGroupIndex(positions.build(), toColumnStatistics(hiveWriterVersion, rowIndexEntry.getStatistics(), true));
    }