public void AddToSet()
        {
            Predicate <int> Even = x => x % 2 == 0;

            Even = Even.AddToSet(1, 3, 5);
            Assert.True(Even(1));
            Assert.True(Even(3));
            Assert.True(Even(2));
            Assert.True(Even(10));
            Assert.True(Even(5));
        }