public static void SubTest()

        {

            DateTime beforeDT = System.DateTime.Now;

            int[] a = new int[] { , , , , , , , , , , , , , , , , , , , ,  };

            //Shuffle(a) is the function you want to test.

            Shuffle(a);

            DateTime afterDT = System.DateTime.Now;

            TimeSpan ts = afterDT.Subtract(beforeDT);

            Console.WriteLine("DateTime costed for Shuffle function is: {0}ms",ts.TotalMilliseconds);

        }

 /// <summary>

        /// 测试for循环优化

        /// </summary>

        /// <returns></returns>

        [HttpGet("test")]

        public ActionResult<ApiResponse> test()

        {

            var result = new ApiResponse();

           Stopwatch sw = new Stopwatch();

           sw.Start();

           //耗时程序

            sw.Stop();

            TimeSpan ts = sw.Elapsed;

            Console.WriteLine("DateTime costed for Shuffle function is: {0}ms", ts.TotalMilliseconds);

            return result;

        }