public async Task <List <DeckModel> > GetStandardDecksAsync()
        {
            var deckEntities = await deckRepository.GetStandardDecksAsync();

            var decks = deckEntities.ConvertAll(deck => deckMapper.Map(deck));

            foreach (var deck in decks)
            {
                var cards = await cardRepository.GetCardsByDeckAsync(deck.Id);

                deck.CardsCount = cards.Count;
            }

            return(decks);
        }