public static async Task<TimeSpan> RunTasksAsync<T>(this IEnumerable<T> source, int maxDegreeOfParallelism, Func<T, Task> body)
        {
            SemaphoreSlim semaphore = new SemaphoreSlim(maxDegreeOfParallelism);
            List<Task> tasks = new List<Task>();

            Stopwatch stopwatch = new Stopwatch();
            stopwatch.Start();

            foreach (T item in source)
            {
                var task = Task.Run(async () =>
                {
                    try
                    {
                        await semaphore.WaitAsync();

                        await body(item);
                        return true;
                    }
                    finally
                    {
                        semaphore.Release();
                    }
                });
                tasks.Add(task);
            }
            await Task.WhenAll(tasks);

            stopwatch.Stop();
            return (stopwatch.Elapsed);
        }