 
         func configure(dataSource: DataSource) {
             textLabel?.text = dataSource.title
+            accessoryType   = .detailButton
         }
     }
 

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    private func setupDataSources() {

        super.viewDidLoad()

        navigationItem.title = "TableView"
        navigationItem.rightBarButtonItem = editButtonItem

        view.addSubview(sampleTableView)
        setupDataSources()
