public async Task UpdateAsync_UpdatingUserToDisabled_UpdatesUser()
        {
            var context = UserRepositoryTestContext.Setup();

            var user = ApplicationUserBuilder
                       .Create()
                       .WithDisabled(false)
                       .Build();

            context.ContextInMemory.Users.Add(user);
            context.ContextInMemory.SaveChanges();

            user.MarkAsDisabled();

            await context.UserRepository.UpdateAsync(user);

            context.ContextInMemory.Users.First().Disabled.Should().BeTrue();
        }
        public static void UpdateAsync_UserIsNull_ReturnsNullException()
        {
            var context = UserRepositoryTestContext.Setup();

            Assert.ThrowsAsync <ArgumentNullException>(async() => await context.UserRepository.UpdateAsync(null));
        }
 static async Task TestAsync()
 {
     var context = UserRepositoryTestContext.Setup();
     await context.UserRepository.UpdateAsync(null);
 }