presto-spi/src/main/java/io/prestosql/spi/block/Int128ArrayBlockBuilder.java/Int128ArrayBlockBuilder/getLong
class Int128ArrayBlockBuilder:    @Override
    public long getLong(int position, int offset)
    {
        checkReadablePosition(position);
        if (offset == 0) {
            return values[position * 2];
        }
        if (offset == 8) {
            return values[(position * 2) + 1];
        }
        throw new IllegalArgumentException("offset must be 0 or 8");
    }