         
         let pageViewController = UIPageViewController(transitionStyle: .scroll,
                                                       navigationOrientation: navigationOrientation,
-                                                      options: convertToOptionalUIPageViewControllerOptionsKeyDictionary(pageViewControllerOptions))
+                                                      options: pageViewControllerOptions)
         pageViewController.delegate = self
         pageViewController.dataSource = self
         self.pageViewController = pageViewController

        return nil
    }
}

// Helper function inserted by Swift 4.2 migrator.
fileprivate func convertToOptionalUIPageViewControllerOptionsKeyDictionary(_ input: [String: Any]?) -> [UIPageViewController.OptionsKey: Any]? {
	guard let input = input else { return nil }
	return Dictionary(uniqueKeysWithValues: input.map { key, value in (UIPageViewController.OptionsKey(rawValue: key), value)})
}

// Helper function inserted by Swift 4.2 migrator.
fileprivate func convertFromUIPageViewControllerOptionsKey(_ input: UIPageViewController.OptionsKey) -> String {
	return input.rawValue
}

    }
    
    /// The options to be passed to a UIPageViewController instance.
    internal var pageViewControllerOptions: [UIPageViewController.OptionsKey: Any]? {
        var options = [UIPageViewController.OptionsKey: Any]()
        
        if interPageSpacing > 0.0 {
            options[.interPageSpacing] = interPageSpacing
        }
        
        guard options.count > 0 else {
