public async Task RefreshCollections()
        {
            this.Collections = new List <CollectionModel>();
            FeedResponse <DocumentCollection> collections;

            using (PerformanceWatcher.Start("ReadCollectionFeed"))
            {
                collections = await this._client.ReadDocumentCollectionFeedAsync(_db.SelfLink);
            }

            foreach (DocumentCollection collection in collections)
            {
                CollectionModel model = new CollectionModel(_client, this, collection);
                this.Collections.Add(model);
            }
        }