public void Test_Negative()
        {
            var controller = new EvenController();

            var t = controller.Get(-2);

            Assert.AreEqual(1, t.Count());

            Assert.AreEqual(2, t.ElementAt(0));
        }
        public void Test_Positive()
        {
            var controller = new EvenController();
            var t = controller.Get(10);

            Assert.AreEqual(2, t.ElementAt(0));
            Assert.AreEqual(4, t.ElementAt(1));
            Assert.AreEqual(6, t.ElementAt(2));
            Assert.AreEqual(8, t.ElementAt(3));
            Assert.AreEqual(10, t.ElementAt(4));
        }