public CustomerViewModel(FECustomer customer, CustomerRepository customerRepository)
        {
            if (customer == null)
                throw new ArgumentNullException("customer");

            if (customerRepository == null)
                throw new ArgumentNullException("customerRepository");

            _customer = customer;
            _customerRepository = customerRepository;
        }
        public AllCustomersViewModel(CustomerRepository customerRepository)
        {
            if (customerRepository == null)
                throw new ArgumentNullException("customerRepository");

            base.DisplayName = StringsConstants.AllCustomersViewModel_DisplayName;

            _customerRepository = customerRepository;

            // Subscribe for notifications of when a new customer is saved.
            _customerRepository.CustomerAdded += this.OnCustomerAddedToRepository;

            // Populate the AllCustomers collection with CustomerViewModels.
            this.CreateAllCustomers();
        }
        public MainWindowViewModel()
        {
            base.DisplayName = StringsConstants.MainWindowViewModel_DisplayName;

            _customerRepository = new CustomerRepository();
        }