public void TestNewCustomerIsAddedProperly()
        {
            var target = new ContactRepository(Constants.CONTACT_DATA_FILE);
            var contact = Contact.CreateNewContact();

            bool eventArgIsValid = false;
            target.ContactAdded += (sender, e) => eventArgIsValid = (e.NewContact == contact);
            target.AddContact(contact);

            Assert.IsTrue(eventArgIsValid, "Invalid NewContact property");
            Assert.IsTrue(target.ContainsContact(contact), "New contact was not added");
        }