presto-spi/src/main/java/io/prestosql/spi/block/Int128ArrayBlock.java/Int128ArrayBlock/getLong
class Int128ArrayBlock:    @Override
    public long getLong(int position, int offset)
    {
        checkReadablePosition(position);
        if (offset == 0) {
            return values[(position + positionOffset) * 2];
        }
        if (offset == 8) {
            return values[((position + positionOffset) * 2) + 1];
        }
        throw new IllegalArgumentException("offset must be 0 or 8");
    }