创建用于Visual Studio单元测试的模拟对象的“首选”方法是什么？

I am aware of Castle's DynamicProxy and RhinoMocks, but I was wondering if, given the fact that Microsoft has introduced unit testing as a first class feature of Visual Studio, whether they have provided any standardized object mocking mechanism to accompany it?I am aware of Castle's DynamicProxy and RhinoMo