private async void Delete(object sender, EventArgs e)
        {
            Button button = (Button)sender;
            int    notification_to_delete = (int)button.CommandParameter;

            HttpResponseMessage response = await NotificationRequest.DeleteNotification(notification_to_delete);

            if (response.IsSuccessStatusCode)
            {
                try
                {
                    OutputNotification obs_to_remove = Notifications.Find(OutputNotification => OutputNotification.Notification.Id == notification_to_delete);
                    Notifications.Remove(obs_to_remove);
                    MyCollectionView.ItemsSource = null;
                    MyCollectionView.ItemsSource = Notifications;
                    await DisplayAlert("Success!", "Notification removed", "OK");
                }
                catch (Exception ex)
                {
                    await DisplayAlert("Error!", "Something went wrong", "OK");
                }
            }
            else
            {
                if (response.StatusCode == System.Net.HttpStatusCode.BadGateway)
                {
                    await DisplayAlert("Attention!!!", "No connection with the server", "OK");
                }
                if (response.StatusCode == System.Net.HttpStatusCode.BadRequest)
                {
                    await DisplayAlert("Try Again!", "Invalid request", "OK");
                }
            }
        }