Tests.DateTime_immutability_tests.AddMonths_creates_new_immutable_DateTime C# (CSharp) Method

        public void AddMonths_creates_new_immutable_DateTime()
        {
            var jan1st = new DateTime(2014, 01, 01);
            var feb1st = jan1st.AddMonths(1);

            // first object remains unchanged
            Assert.AreEqual(new DateTime(2014, 01, 01), jan1st);

            // second object is a new immutable instance
            Assert.AreEqual(new DateTime(2014, 02, 01), feb1st);
        }