presto-orc/src/main/java/io/prestosql/orc/AbstractOrcDataSource.java/LazyBufferLoader/load
class LazyBufferLoader:        private void load()
        {
            if (bufferSlice != null) {
                return;
            }
            try {
                bufferSlice = readFully(diskRange.getOffset(), diskRange.getLength());
            }
            catch (IOException e) {
                throw new UncheckedIOException(e);
            }
        }