let items = PublishSubject<[(menu: String, width: CGFloat, content: UIViewController)]>()

    override func viewDidLoad() {
        super.viewDidLoad()
        
        menuViewController?.register(type: TitleLabelMenuViewCell.self, forCellWithReuseIdentifier: "identifier")
        menuViewController?.registerFocusView(view: UnderlineFocusView())
        
        // PagingMenuViewControllerDataSource
        items.asObserver()
            .map { items in items.map({ ($0.menu, $0.width) }) }
            .bind(to: menuViewController.rx.items(
                cellIdentifier: "identifier",
                cellType: TitleLabelMenuViewCell.self)
            ) { _, model, cell in
                cell.titleLabel.text = model
            }
            .disposed(by: disposeBag)
        
        // PagingContentViewControllerDataSource
        items.asObserver()
            .map { items in items.map({ $0.content }) }
            .bind(to: contentViewController.rx.viewControllers())
            .disposed(by: disposeBag)
        
        // PagingMenuViewControllerDelegate
        menuViewController.rx.itemSelected.asObservable().subscribe(onNext: { [weak self] (page, prev) in
            self?.contentViewController.scroll(to: page, animated: true)
        }).disposed(by: disposeBag)
        
        // PagingContentViewControllerDelegate
        contentViewController.rx.didManualScroll.asObservable().subscribe(onNext: { [weak self] (index, percent) in
            self?.menuViewController.scroll(index: index, percent: percent, animated: false)
        }).disposed(by: disposeBag)
    }