@Override
    public int hashCode() {
        long xor = mostSignificantBits ^ leastSignificantBits;
        return (int) (xor >> 32) ^ (int) xor;
    }
@Test
    public void testHashCode() {
        Uuid id1 = new Uuid(16L, 7L);
        Uuid id2 = new Uuid(1043L, 20075L);
        Uuid id3 = new Uuid(104312423523523L, 200732425676585L);
        
        assertEquals(23, id1.hashCode());
        assertEquals(19064, id2.hashCode());
        assertEquals(-2011255899, id3.hashCode());
    }