public void Throws_exception_for_non_nullable_props()
{
var user = GetUserWith(delegate { });
SaveShouldNotFail(user);
user = GetUserWith(usr => usr.Email = null);
SaveShouldFail(user);
user = GetUserWith(usr => usr.Password = null);
SaveShouldFail(user);
user = GetUserWith(usr => usr.UserName = null);
SaveShouldFail(user);
}