presto-orc/src/main/java/io/prestosql/orc/metadata/CompressedMetadataWriter.java/CompressedMetadataWriter/writeRowIndexes
class CompressedMetadataWriter:    public Slice writeRowIndexes(List<RowGroupIndex> rowGroupIndexes)
            throws IOException
    {
        metadataWriter.writeRowIndexes(buffer, rowGroupIndexes);
        return getSliceOutput();
    }