             
             switch currentView {
             case .savedArticles:
+                removeChild(readingListsCollectionViewController)
                 addChild(savedArticlesCollectionViewController)
-            case .readingLists:
+            case .readingLists :
                 removeChild(savedArticlesCollectionViewController)
+                addChild(readingListsCollectionViewController)
             }
         }
     }

        vc.didMove(toParentViewController: self)
    }
    
    fileprivate func removeChild(_ vc: UICollectionViewController) {
        vc.view.removeFromSuperview()
        vc.willMove(toParentViewController: nil)
        vc.removeFromParentViewController()

@objc(WMFSavedViewController)
class SavedViewController: UIViewController, ArticleCollectionViewControllerDelegate {

    fileprivate var savedArticlesCollectionViewController: SavedCollectionViewController!
    
    fileprivate lazy var readingListsCollectionViewController: ReadingListsCollectionViewController? = {
        guard let dataStore = dataStore else {
            return nil
        }
        return ReadingListsCollectionViewController(with: dataStore)
    }()

    @IBOutlet weak var containerView: UIView!
    @IBOutlet weak var savedTitleView: UIView!
