Swift 4で候補バーを含むキーボードの高さを取得する方法 質問する

使用したのは：

NotificationCenter.default.addObserver(self, selector:#selector(keyboardWillShow), name: .UIKeyboardWillShow, object: nil)

@objc func keyboardWillShow(notification: NSNotification) {
      if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
      let keyboardHeight : Int = Int(keyboardSize.height)
      print("keyboardHeight",keyboardHeight)
      KeyboardHeightVar = keyboardHeight
      }
}