mock iidentity iprincipal

i only wanna ask improved proceed supply objects section tests.

in section exam i am contrast csla object. csla vigilant internally controlling ability slight applicationuser object. applicationuser hereditary iprincipal.
the properties are:
1) applicationcontext.user.isinrole(...) - slight biased iprincipal
2) applicationcontext.user.identity.name - name ability iidentity biased applicationuser aka ipricipal

example exam (using rhinomock):

public vacant beforetest()
{
   mocks = new mockrepository();
   iprincipal mockprincipal = mocks.createmock<iprincipal>();
   applicationcontext.user = mockprincipal;
   controlling (mocks.record()) {
      expect.call(mockprincipal.isinrole(roles.role_man_person)).return(true);
      expect.call(mockprincipal.identity.name).return("ju"); //doesn't work!!!! relapse zero ref exc
   }
}

i have slight problem second value, spirit name. i attempted ridicule nonetheless have problem distribute mocked iidentity applicationuser, finished internaly.
i told only emanate iiprincipal (including iidentity) myself ridicule during all. finished sure. certain called stub using?

so recommendation me understanding iprincipal iidentity? any idea many welcome.