public CurrencyViewModel(
            IInitializationFacade initializationFacade,
            CurrencyDescriptionHelper currencyDescriptionHelper)
        {
            _initializationFacade      = initializationFacade;
            _currencyDescriptionHelper = currencyDescriptionHelper;

            CurrencyRates = new ObservableCollection <Rate>();

            PrepareDataAsync();
        }
        public void Setup()
        {
            var dictionary = new Dictionary <string, decimal>();

            dictionary.Add("USD", new decimal(1.3));
            dictionary.Add("PLN", new decimal(4.3));
            _dictionarySize = dictionary.Count;

            var mockInitializationFacade = new Mock <IInitializationFacade>(MockBehavior.Strict);

            mockInitializationFacade.Setup(f => f.GetData()).ReturnsAsync(new Currency
            {
                Base  = "EUR",
                Date  = DateTime.Now,
                Rates = dictionary
            });

            var initializationFacade = mockInitializationFacade.Object;

            var currencyDescriptionHelper = new CurrencyDescriptionHelper();

            _testingViewModel = new CurrencyViewModel(initializationFacade, currencyDescriptionHelper);
        }