public void TestPasswordCheckerServiceConstructor()
        {
            var stub = new FakeRepositoryStub();

            var passwordColelction = new List <string> {
                "123asdfg", "123asdfg1", "asdfgjkl"
            };

            foreach (var password in passwordColelction)
            {
                stub.Create(password);
            }

            var checker = new PasswordCheckerService(stub, CustomPasswordValidator.Instance);

            // Get private repository field from PasswordCheckerService using reflection.
            BindingFlags bindFlags = BindingFlags.Instance | BindingFlags.NonPublic;
            FieldInfo    field     = checker.GetType().GetField("passwordRepository", bindFlags);
            var          actual    = ((FakeRepositoryStub)field.GetValue(checker)).Passwords;

            CollectionAssert.AreEqual(passwordColelction, actual);
        }