Simple Navigator implementation

navigator.swift

class Navigator {
    func handle(navigation: Navigation, animated: Bool = true) {
        switch navigation {
        case .section(let section):
            tabBarController().selectedIndex = section.rawValue
            
        case .modal(let screen):
            topMostViewController().present(
                screen.viewController(),
                animated: animated
            )
            
        case .push(let screen):
            currentNavigationController().pushViewController(
                screen.viewController(),
                animated: animated
            )
        }
    }
}