public void TearDown()
 {
     _database = null;
     _hostService = null;
     _tripService = null;
     _newsletterService = null;
     _newsletterController = null;
 }
 public void SetUp()
 {
     _database = new FileSystemDatabase();
     _hostService = new HostService(_database);
     _tripService = new TripService(_database);
     _newsletterService = new NewsletterService(_database);
     _newsletterController = new NewsletterController(_newsletterService, 
                                                      _hostService, 
                                                      _tripService);
 }