presto-spi/src/main/java/io/prestosql/spi/type/UnscaledDecimal128Arithmetic.java/UnscaledDecimal128Arithmetic/unscaledDecimal
class UnscaledDecimal128Arithmetic:    public static Slice unscaledDecimal(long unscaledValue)
    {
        long[] longs = new long[NUMBER_OF_LONGS];
        if (unscaledValue < 0) {
            longs[0] = -unscaledValue;
            longs[1] = SIGN_LONG_MASK;
        }
        else {
            longs[0] = unscaledValue;
        }
        return Slices.wrappedLongArray(longs);
    }