     }
     
     override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
-        hintButton.titleLabel?.setFont(with: .systemMedium, style: .subheadline, traitCollection: traitCollection)
+        hintButton?.titleLabel?.setFont(with: .systemMedium, style: .subheadline, traitCollection: traitCollection)
     }
     
     public weak var delegate: ReadingListHintViewControllerDelegate?

            return
        }
        view.backgroundColor = theme.colors.disabledLink
        hintButton.setTitleColor(theme.colors.link, for: .normal)
        confirmationButton.setTitleColor(theme.colors.link, for: .normal)
    }
}

    var dataStore: MWKDataStore?
    fileprivate var theme: Theme = Theme.standard
    
    var article: WMFArticle? {
        didSet {
            guard article != oldValue else {
                return
            }
            hintButton?.setTitle("Add \(articleTitle) to reading list", for: .normal)
        }
    }
    
    private var articleTitle: String {
        return article?.displayTitle ?? "article"
    }
    
    @IBOutlet weak var hintView: UIView!
    @IBOutlet weak var hintButton: AlignedImageButton?
    @IBOutlet weak var confirmationView: UIView!
    @IBOutlet weak var confirmationImageView: UIImageView!
    @IBOutlet weak var confirmationButton: UIButton!
