public MainViewModel(IFeedPreviewsLoader feedPreviews)
        {
            _feedPreviews = feedPreviews;

			AddSubscriptionCommand = NavigateCommand.WithParameter(() => Locator.Current.GetService<AddSubscriptionViewModel>());
			Feeds = feedPreviews.CreateCollection().CreateDerivedCollection(f => f, null, FreshFirstOrderer);

            this.WhenActivated(d => feedPreviews.Load());
        }
 public CachableFeedsLoader(IFeedPreviewsLoader inner, IBackgroundDownloader downloader, IBlobCache cache)
 {
     _inner = inner;
 }