     case TAG_B_RETURN:
       if isTextField() {
         let textField = textView as! UITextField
-        textField.delegate?.textFieldShouldReturn?(textField)
+        let _ = textField.delegate?.textFieldShouldReturn?(textField)
       }
       else if isTextView() {
         textView?.insertText("\n")

   - parameter at: the index of the button
   - parameter action: the block of code to execute when the UIControlEvents.touchUpInside event is triggered for this button
   */
  open func setAdditionalButton(title title: String, at index: AdditionalButtonIndex, action: @escaping () -> Void)
  {
    removeAdditionalButton(at: index)
    

      switch self {
      case .save, .search, .go:
        return UIColor.white
      case .custom(let _, let actionButton) where actionButton:
        return UIColor.white
      default:
        return nil
