sealed class Tester : Tester<object>
    {
        private readonly Action action;

        public Tester(Action action, int times)
        {
            this.action = action;
            this.times = times;
        }

        new public async Task<long> Run()
        {
            var stopWatch = new Stopwatch();
            long timeSpent = 0;

            await Task.Run(() =>
            {
                for (int i = 0; i < times; i++)
                {
                    stopWatch.Start();
                    action();
                    stopWatch.Stop();

                    timeSpent += stopWatch.ElapsedMilliseconds;
                }
            });

            return timeSpent / times;
        }
    }

    class Tester<T>
    {
        private readonly Action<T> action;
        private readonly Func<T> seed;
        private readonly bool useSeed;
        protected int times;

        protected Tester() { }

        public Tester(Action<T> action, int times, Func<T> seed)
        {
            this.action = action;
            this.times = times;
            this.seed = seed;
            useSeed = true;
        }

        public async Task<long> Run()
        {
            var stopWatch = new Stopwatch();
            long timeSpent = 0;

            await Task.Run(() =>
            {
                for (int i = 0; i < times; i++)
                {
                    var seedValue = seed();
                    stopWatch.Start();
                    action(seedValue);
                    stopWatch.Stop();

                    timeSpent += stopWatch.ElapsedMilliseconds;
                }
            });

            return timeSpent/times;
        }
    }