public async Task CreateAsync_EmailExists_Fail()
        {
            var store = new StubUserStore();

            store.Users.Add(GetUser());
            var manager = new CustomUserManager(store);
            var user    = GetUser();

            var result = await manager.CreateAsync(user, user.Password);

            Assert.IsFalse(result.Succeeded);
        }
        public async Task CreateAsync_UserNameExists_Succeeded()
        {
            var store = new StubUserStore();

            store.Users.Add(GetUser());
            var manager = new CustomUserManager(store);
            var user    = GetUser();

            user.Email = "*****@*****.**";

            var result = await manager.CreateAsync(user, user.Password);

            Assert.IsTrue(result.Succeeded);
        }