public async Task When__UserStore_Create_User__Expect__User_Created()
{
ApplicationUser user = new ApplicationUser();
user.UserName = "******";
await _userStore.CreateAsync(user).ConfigureAwait(false);
ApplicationUser savedUser = await _userStore.FindByNameAsync(user.UserName).ConfigureAwait(false);
Assert.That(savedUser, Is.Not.Null, "User is not created");
Assert.That(savedUser.UserName, Is.EqualTo(user.UserName), "Wrong user ");
}