private async Task LoadSitesImpl()
        {
            if (!AvailableSites.Any())
            {
                var sites = await NetworkApi.Sites();

                AvailableSites.Clear();
                AvailableSites.AddRange(sites.Items.Select(site => new SiteViewModel(site)));
                SelectedSite = AvailableSites.FirstOrDefault();
            }
        }