public void RemoveEvens_InputLettersNumbers()
        {
            var input    = "aa, b, ccc, ddd, 11, ef, gh, 98";
            var shouldBe = "aa, ccc, 11, gh";
            var reallyIs = StupidMaths.RemoveEvens(input);

            Assert.AreEqual(shouldBe, reallyIs);
        }
        public void RemoveEvens_InputLetters()
        {
            var input    = "a, b, c, d, e, f, g, h";
            var shouldBe = "a, c, e, g";
            var reallyIs = StupidMaths.RemoveEvens(input);

            Assert.AreEqual(shouldBe, reallyIs);
        }
        public void RemoveEvens_Commas()
        {
            var input    = ",,,,,";
            var shouldBe = ",,";
            var reallyIs = StupidMaths.RemoveEvens(input);

            Assert.AreEqual(shouldBe, reallyIs);
        }
        public void RemoveEvens_TwoElements()
        {
            var input    = "1, 5.2";
            var shouldBe = "1";
            var reallyIs = StupidMaths.RemoveEvens(input);

            Assert.AreEqual(shouldBe, reallyIs);
        }
        public void RemoveEvens_OneElement()
        {
            var input    = "10";
            var shouldBe = "10";
            var reallyIs = StupidMaths.RemoveEvens(input);

            Assert.AreEqual(shouldBe, reallyIs);
        }
        public void RemoveEvens_SuggestedTest()
        {
            var input    = "1.2, 2, 3.5";
            var shouldBe = "1.2, 3.5";
            var reallyIs = StupidMaths.RemoveEvens(input);

            Assert.AreEqual(shouldBe, reallyIs);
        }