presto-spi/src/main/java/io/prestosql/spi/type/UnscaledDecimal128Arithmetic.java/UnscaledDecimal128Arithmetic/setRawInt
class UnscaledDecimal128Arithmetic:    private static void setRawInt(Slice decimal, int index, int value)
    {
        unsafe.putInt(decimal.getBase(), decimal.getAddress() + SIZE_OF_INT * index, value);
    }