     func willGetNavigationDelegate() -> SAHistoryNavigationViewControllerDelegate? { return nil }
     func willSetTransitionDelegate(transitionDelegate: SAHistoryNavigationViewControllerTransitionDelegate?) {}
     func willGetTransitionDelegate() -> SAHistoryNavigationViewControllerTransitionDelegate? { return nil }
+    func willSetShowCustomAnimation(showCustomAnimation: Bool) {}
+    func willGetShowCustomAnimation() -> Bool { return true }
 }
 
 extension UIView {

        if !edgeSwiping {
            return nil
        }
    
        return defaultInteractiveTransition
    }

            return willGetTransitionDelegate()
        }
    }
    public var showCustomAnimation: Bool {
        set {
            willSetShowCustomAnimation(showCustomAnimation)
        }
        get {
            return willGetShowCustomAnimation()
        }
    }
    public func showHistory() {}
    public func setHistoryBackgroundColor(color: UIColor) {}
    public func contentView() -> UIView? { return nil }
