public static async Task Task2(IThrottler throttler) { Console.WriteLine("Async throttler..."); var stopwatch = Stopwatch.StartNew(); for (var i = 0; i < 350; i++) { // USe async mode await throttler.WaitForPermissionAsync(); Console.WriteLine($"Async - {i}"); } stopwatch.Stop(); Console.WriteLine($"{stopwatch.Elapsed.TotalSeconds:##.00} s"); }