private async void LoadDataSource(OAuthAccessToken accessToken)
        {
            var f = new Flickr("dbc316af64fb77dae9140de64262da0a", "0781969a058a2745")
                        {
                            OAuthAccessToken = accessToken.Token,
                            OAuthAccessTokenSecret = accessToken.TokenSecret
                        };

            var groups = DefaultViewModel["Groups"] as ObservableCollection<SampleDataGroup>;
            groups.Clear();
            var photostreamGroup = new SampleDataGroup("A", "Your Photos", "Photostream", "", "");
            groups.Add(photostreamGroup);

            var contactsGroup = new SampleDataGroup("A", "Your Contact", "Latest Updates", "", "");
            groups.Add(contactsGroup);

            var favouritesGroup = new SampleDataGroup("A", "Your Favourites", "Favourite Photos", "", "");
            groups.Add(favouritesGroup);

            var photos = await f.PeopleGetPhotosAsync(accessToken.UserId, SafetyLevel.None, null, null, null, null,
                                                      ContentTypeSearch.None, PrivacyFilter.None,
                                                      PhotoSearchExtras.Description | PhotoSearchExtras.LargeUrl, 1,
                                                      30);
            foreach (
                var photo in
                    photos.Select(
                        p => new SampleDataItem(p.PhotoId, p.Title, "", p.LargeUrl, p.Description, p.Description, photostreamGroup))
                )
            {
                photostreamGroup.Items.Add(photo);
            }

            photos =
                await f.PhotosGetContactsPhotosAsync(extras: PhotoSearchExtras.Description | PhotoSearchExtras.LargeUrl | PhotoSearchExtras.OwnerName);
            foreach (
                var photo in
                    photos.Select(
                        p => new SampleDataItem(p.PhotoId, p.Title, p.OwnerName, p.LargeUrl, p.Description, p.Description, contactsGroup))
                )
            {
                contactsGroup.Items.Add(photo);
            }

            photos = await f.FavoritesGetListAsync(extras: PhotoSearchExtras.Description | PhotoSearchExtras.LargeUrl | PhotoSearchExtras.OwnerName);
            foreach (
                var photo in
                    photos.Select(
                        p => new SampleDataItem(p.PhotoId, p.Title, p.OwnerName, p.LargeUrl, p.Description, p.Description, favouritesGroup))
                )
            {
                favouritesGroup.Items.Add(photo);
            }
        }