private async void Window_Drop(object sender, DragEventArgs e)
        {
            var files = (string[])e.Data.GetData(DataFormats.FileDrop);

            if (files.Length > 0)
            {
                _model.DroppedFiles = new List<string>(files);
                _model.SelectedFile = "";

                var shrinker = new ImageShrinkBatcher(_model);
                await shrinker.DoShrinkAsync();
            }
        }
        private async void ShrinkIt_Click(object sender, RoutedEventArgs e)
        {
            if (string.IsNullOrWhiteSpace(_model.SelectedFile) || _model.RequestedSize <= 0)
                return;

            _model.DroppedFiles.Clear();

            var shrinker = new ImageShrinkBatcher(_model);
            await shrinker.DoShrinkAsync();
        }