 
     private var selectionChangeObserver: AnyObject!
     private var toggleObserver: AnyObject!
+    private var pushObserver: AnyObject!
     private var moveObserver: AnyObject!
     private var removalObserver: AnyObject!
     private var itemEditingObserver: AnyObject!

            object: sidebarView,
            queue: nil) { [weak self] in self?.itemWasToggled($0) }

        moveObserver = notificationCenter.addObserver(
            forName: FatSidebarView.didReorderItemNotification,
            object: sidebarView,

        delegate?.sidebar?(self, didChangeSelection: index)
    }

    fileprivate func itemWasPushed(_ notification: Notification) {

        guard let index = notification.userInfo?["index"] as? Int else { return }

        delegate?.sidebar?(self, didPushItem: index)
    }

    fileprivate func itemWasToggled(_ notification: Notification) {

        guard let index = notification.userInfo?["index"] as? Int else { return }

        delegate?.sidebar?(self, didToggleItem: index)
    }

    fileprivate func itemDidMove(_ notification: Notification) {
