presto-spi/src/main/java/io/prestosql/spi/type/UnscaledDecimal128Arithmetic.java/UnscaledDecimal128Arithmetic/getRawLong
class UnscaledDecimal128Arithmetic:    private static long getRawLong(Slice decimal, int index)
    {
        return unsafe.getLong(decimal.getBase(), decimal.getAddress() + SIZE_OF_LONG * index);
    }