public PaymentViewModel()
 {
     CreditCard = new CreditCardViewModel();
     Prepayment = new PrepaymentViewModel();
 }
 public SpecialistPaymentViewModel()
 {
     CreditCard = new CreditCardViewModel();
     Bank = new BankAccountViewModel();
 }
 public CreditCardPaymentViewModel()
 {
     CreditCard = new CreditCardViewModel();
 }