private void OpenNotificationWindow(object obj)
        {
            bool isWindowOpen = false;

            foreach (Window w in Application.Current.Windows)
            {
                if (w is NotificationWindow)
                {
                    isWindowOpen = true;
                    w.Activate();
                }
            }
            if (!isWindowOpen)
            {
                NotificationWindow newwindow = new NotificationWindow();
                newwindow.Show();
            }
        }
        private void DisplayNotification(object sender, EventArgs e)
        {
            bool isWindowOpen = false;

            foreach (Window w in Application.Current.Windows)
            {
                if (w is NotificationWindow || w is NotificationPreviewWindow)
                {
                    isWindowOpen = true;
                }
            }
            if (!isWindowOpen)
            {
                if (NotificationQueue.Count != 0)
                {
                    Notification n = NotificationQueue.First();
                    NotificationQueue.Remove(n);
                    NotificationWindow newWindow = new NotificationWindow();
                    (newWindow.DataContext as NotificationWindowViewModel).Notification = n.NotificationString;
                    newWindow.Show();
                }
            }
        }