private void SaveFavourites() { PersistenceService.DeleteFavourites().Wait(); var favourites = Predictions.Where(x => x.Favourite) .Select(x => new FavouriteDTO { StockId = x.TrainingSession.Stock.GetUniqueId() }).ToList(); if (favourites.Any()) { PersistenceService.SaveFavourites(favourites).Wait(); } }