public void CanUpdate()
        {
            // setup
            string tweet1 = "Hello world";
            string tweet2 = "World Hello";

            // record
            Expect.Call(_twitterApiClient.UpdateWithSource(tweet1, TweetsManager.APP_NAME)).Return(new Status {
                Text = tweet1
            });
            Expect.Call(_twitterApiClient.UpdateWithSource(tweet2, TweetsManager.APP_NAME)).Return(new Status {
                Text = tweet2
            });

            // playback
            _mocks.ReplayAll();
            _tweetsManager.Update(tweet1);
            _tweetsManager.Update(tweet2);

            // assert
            Assert.AreEqual(2, _tweetsManager.All.Count);
            Assert.AreEqual(tweet2, _tweetsManager.All[0].Text);
            Assert.AreEqual(tweet1, _tweetsManager.All[1].Text);
            _mocks.VerifyAll();
        }