在TypeMock中模拟受保护的属性

Question

在尝试模拟基类对象的受保护属性并在执行测试时遇到异常时，我遇到了问题。

这是我的基类，派生类和单元测试的代码片段

//A abstract class that provides external user authentication methods and helpers.
    public abstract class ExternalAuthenticationProvider
    {
        public abstract ExternalLoginResult SessionLogin(string username, string password);
    }

    //BaseAccountController has protected property of type 'ExternalAuthenticationProvider'
    public class BaseAccountController : BaseController
    {
        public BaseAccountController();
        protected ExternalAuthenticationProvider Provider { get; }
    }

    //Deriver class and AccountController inherits BaseAccountController
    public class AccountController : BaseAccountController
    {
        public ActionResult RecruitLogin(MvcLoginModel model)
        {
            var result = Provider.SessionLogin(model.Username, model.Password);
        }
    }

    //Here is my Unit Test method
    [TestMethod, Isolated]
    public void LoginTest_Post()
    {
        //Arrange
        var fakeModel = Isolate.Fake.Instance<MvcLoginModel>();
        var fakeResult = Isolate.Fake.Instance<ExternalLoginResult>();

        var fakePovider = Isolate.NonPublic.Fake.Instance(typeof(ExternalAuthenticationProvider));
        var fakeController = Isolate.Fake.Instance<BaseAccountController>(Members.ReturnRecursiveFakes);

        Isolate.NonPublic.WhenCalled(fakePovider, "SessionLogin").WillReturn(fakeResult);
        Isolate.NonPublic.Property.WhenGetCalled(fakeController, "Provider").ReturnRecursiveFake(typeof(ExternalAuthenticationProvider));

        //Act
        var _controller = new AccountController();
        var result = _controller.RecruitLogin(fakeModel, fakeUrl) as ViewResult;

        //Asert todo...
    }

在运行测试时，受保护的成员“ Provider”由于以下错误而失败，并且没有获取fakeProvider对象以避免基类依赖。

我正在使用TypeMock框架，无法继续执行此步骤，我的想法是也伪造基类和受保护的属性。

在这种情况下，有人可以建议我采取正确的方法吗？