presto-orc/src/main/java/io/prestosql/orc/stream/OrcChunkLoader.java/OrcChunkLoader/create
class OrcChunkLoader:    static OrcChunkLoader create(
            OrcDataReader dataReader,
            Optional<OrcDecompressor> decompressor,
            AggregatedMemoryContext memoryContext)
    {
        requireNonNull(dataReader, "dataReader is null");
        requireNonNull(decompressor, "decompressor is null");
        requireNonNull(memoryContext, "memoryContext is null");

        if (decompressor.isPresent()) {
            return new CompressedOrcChunkLoader(dataReader, decompressor.get(), memoryContext);
        }
        return new UncompressedOrcChunkLoader(dataReader, memoryContext);
    }