public OrderViewModel(EmailSender emailSender, ReceiptPrinter receiptPrinter, OrderDao orderDao, RecommendationEngine engine, ReceiptDao receiptDao)
 {
     _emailSender          = emailSender;
     _receiptPrinter       = receiptPrinter;
     _orderDao             = orderDao;
     _recommendationEngine = engine;
     _receiptDao           = receiptDao;
     Recommendations       = new ObservableCollection <Recommendation>();
 }
 public OrderViewModel(EmailSender emailSender, ReceiptPrinter receiptPrinter, OrderDao orderDao, RecommendationEngine engine, ReceiptDao receiptDao)
 {
     _emailSender = emailSender;
     _receiptPrinter = receiptPrinter;
     _orderDao = orderDao;
     _recommendationEngine = engine;
     _receiptDao = receiptDao;
     Recommendations = new ObservableCollection<Recommendation>();
 }