 
         NotificationCenter.default().addObserver(
             self, selector: .textDidChange,
-            name: NSNotification.Name.UITextFieldTextDidChange,
+            name: .UITextFieldTextDidChange,
             object: self
         )
     }

import KGNPreferredFontManager

private extension Selector {
    static let textDidChange = #selector(UITextInputDelegate.textDidChange(_:))
}

/// Subclass of `PreferredFontTextField`. This implementation also allows

        NotificationCenter.default().removeObserver(self)
    }

    @objc private func textDidChange() {
        self.updatePlaceholderAndAutoComplete()
    }

