presto-spi/src/main/java/io/prestosql/spi/type/UnscaledDecimal128Arithmetic.java/UnscaledDecimal128Arithmetic/copyUnscaledDecimal
class UnscaledDecimal128Arithmetic:    private static void copyUnscaledDecimal(Slice from, Slice to)
    {
        setRawLong(to, 0, getRawLong(from, 0));
        setRawLong(to, 1, getRawLong(from, 1));
    }