         }
     }
 
+    /// The right view controller.
     public var rightViewController: UIViewController? {
         willSet {
             if newValue == nil {

        return gestureRecognizer
    }()

    public private(set) lazy var rightDrawerCloseWithPanGestureRecognizer: UIPanGestureRecognizer = {
        let gestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(didRecognizePanGesture))
        gestureRecognizer.delegate = self

        return gestureRecognizer
    }()

    /// The gesture recognizer used to open the right drawer from the right edge of the screen.
    public private(set) lazy var rightDrawerOpenWithScreenEdgePanGestureRecognizer: UIScreenEdgePanGestureRecognizer = {
        let gestureRecognizer = UIScreenEdgePanGestureRecognizer(target: self, action: #selector(didRecognizeScreenEdgePanGesture))
        gestureRecognizer.delegate = self
