 
     func _init() {
         [ NSNotification.Name.UIKeyboardWillChangeFrame, NSNotification.Name.UIKeyboardWillHide ].forEach {
-            NotificationCenter.default.addObserver(forName: $0, object: nil, queue: .main) { notification in
+            let observer = NotificationCenter.default.addObserver(forName: $0, object: nil, queue: .main) { notification in
                 switch notification.name {
                 case NSNotification.Name.UIKeyboardWillChangeFrame:
                     self.logger?.logDebug(message: String(format: "[%@] UIKeyboardWillChangeFrame", instanceType(self)))

        _init()
    }

}

// MARK: Public

        for inputView in inputViews {
            inputView.resignFirstResponder()
        }
    }

    func removeKeyboardObservers() {
        notificationObservers.forEach { NotificationCenter.default.removeObserver($0) }
    }

}
