SideMenuController couldn't be insert into UINavigationController?

[leviluo]

when i test example code like this:
let contentViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "ContentNavigation")
let menuViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "MenuNavigation")
let sideMenuController = SideMenuController(contentViewController: contentViewController, menuViewController: menuViewController)
UIApplication.shared.keyWindow?.rootViewController = UINavigationController.init(rootViewController: sideMenuController)

the SideMenuController can't work well,and view will move below 88px