Questions about SideMenuPresentationController present and dismiss change interactivePopGestureRecognizer.isEnabled

[MichaelHuyp]

func presentationTransitionDidEnd(_ completed: Bool) {
        guard completed else {
            snapshotView?.removeFromSuperview()
            dismissalTransitionDidEnd(!completed)
            return
        }

        guard let presentedViewController = presentedViewController,
            let presentingViewController = presentingViewController
            else { return }

        addParallax(to: presentingViewController.view)

        if let topNavigationController = presentingViewController as? UINavigationController {
            interactivePopGestureRecognizerEnabled = interactivePopGestureRecognizerEnabled ?? topNavigationController.interactivePopGestureRecognizer?.isEnabled
            topNavigationController.interactivePopGestureRecognizer?.isEnabled = false
        }

        containerViewWillLayoutSubviews()
        config.presentationStyle.presentationTransitionDidEnd(to: presentedViewController, from: presentingViewController, completed)
   }

func dismissalTransitionDidEnd(_ completed: Bool) {
        guard completed else {
            if let snapshotView = snapshotView, let presentingViewController = presentingViewController {
                presentingViewController.view.addSubview(snapshotView)
            }
            presentationTransitionDidEnd(!completed)
            return
        }

        guard let presentedViewController = presentedViewController,
            let presentingViewController = presentingViewController
            else { return }

        statusBarView?.removeFromSuperview()
        removeStyles(from: presentingViewController.containerViewController.view)

        if let interactivePopGestureRecognizerEnabled = interactivePopGestureRecognizerEnabled,
            let topNavigationController = presentingViewController as? UINavigationController {
            topNavigationController.interactivePopGestureRecognizer?.isEnabled = interactivePopGestureRecognizerEnabled
        }

        presentingViewController.view.isUserInteractionEnabled = true
        config.presentationStyle.dismissalTransitionDidEnd(to: presentedViewController, from: presentingViewController, completed)
    }

I noticed that you changed the enable attribute of the root navigation controller when the sidebar was expanded and collapsed. Why is this?