if #available(iOS 11.2, *)
    {
        let keyPath = "textContentView.provider"
        if self.window != nil {
            let provider = self.value(forKeyPath: keyPath)
            if provider == nil {
                self.setValue(self, forKeyPath: keyPath)
            }
        }else{
            self.setValue(nil, forKeyPath: keyPath)
        }
    }