public void TestAlphaNumericOnly()
        {
            Assert.AreEqual("", StringUtils.AlphaNumericOnly("~!@#$%^&*()_+|}{	"));

            Assert.AreEqual("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890",
                            StringUtils.AlphaNumericOnly("abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ.1234567890"));

            Assert.AreEqual("ca761232ed4211cebacd00aa0057b223",
                            StringUtils.AlphaNumericOnly("{ca761232-ed42-11ce-bacd-00aa0057b223}"));
        }