public void Factorial1()
        {
            var retFunc = Factorial.GetFactorialFunction();

            Assert.AreEqual(1, retFunc(1));
        }
        public void Factorial6()
        {
            var retFunc = Factorial.GetFactorialFunction();

            Assert.AreEqual(720, retFunc(6));
        }
        public void Factorial5()
        {
            var retFunc = Factorial.GetFactorialFunction();

            Assert.AreEqual(120, retFunc(5));
        }
        public void Factorial4()
        {
            var retFunc = Factorial.GetFactorialFunction();

            Assert.AreEqual(24, retFunc(4));
        }
        public void Factorial3()
        {
            var retFunc = Factorial.GetFactorialFunction();

            Assert.AreEqual(6, retFunc(3));
        }
        public void Factorial2()
        {
            var retFunc = Factorial.GetFactorialFunction();

            Assert.AreEqual(2, retFunc(2));
        }