Time/Memory watcher for C#

PerformanceWatcher.cs

        public static double TimeWatcher(Action action)
        {
            System.Diagnostics.Stopwatch watch = new System.Diagnostics.Stopwatch();
            watch.Start();
            action();
            watch.Stop();
            var useTime = (double) watch.ElapsedMilliseconds/1000;
            return useTime;
        }

        public static long MemoryWatcher(Action action)
        {
            long start = GC.GetTotalMemory(true);
            action();
            GC.Collect();
            GC.WaitForFullGCComplete();
            long end = GC.GetTotalMemory(true);
            long useMemory = (end - start)/(1024*1024);
            return useMemory;
        }