ThemeProtocol.swift

protocol ThemeProtocol {
    func addThemeChangeObserver()
    func configureSubviewsColors()
}

extension ThemeProtocol  {
    func addThemeChangeObserver() {
        if #available(iOS 13, *) {
        } else {
            NotificationCenter.default.addObserver(forName: NSNotification.Name(rawValue: "themeChange"),
                                                   object: nil,
                                                   queue: OperationQueue.main) { _ in
                self.configureSubviewsColors()
            }
        }
    }

}