AsyncIsNotParallel.MainWindow.bttnStart_Click C# (CSharp) Method

        private async void bttnStart_Click(object sender, RoutedEventArgs e)
        {
            txtStatus.Text = "Started";
            sw.Restart();
            Task t1 = DoWorkAsync(Colors.Red, 0, 200);
            Task t2 = DoWorkAsync(Colors.Blue, 1, 300);
            Task t3 = DoWorkAsync(Colors.Green, 2, 500);
            await Task.WhenAll(t1, t2, t3);
            sw.Stop();
            txtStatus.Text = $"Finished after {sw.ElapsedMilliseconds}";
        }