'Verify that a viewpoint can be retrieved after authenticating with
cred.'

def test_view(self):

    self.portal.registerChecker(checkers.InMemoryUsernamePasswordDatabaseDontUse(user='pass'))
    d = self.clientFactory.login(credentials.UsernamePassword('user', 'pass'), 'BRAINS!')
    def cbLogin(perspective):
        return perspective.callRemote('getViewPoint')
    d.addCallback(cbLogin)
    def cbView(viewpoint):
        return viewpoint.callRemote('check')
    d.addCallback(cbView)
    d.addCallback(self.assertTrue)
    self.establishClientAndServer()
    self.pump.flush()
    return d
