      - returns: Self
      */
     
+    @discardableResult
     open func addTextField(_ configurationHandler: ((_ textField: UITextField) -> Void)?) -> Self{
         guard alert?.preferredStyle == .alert else {
             return self

     - returns: Self
     */
    
    open func addAction(_ title: String?,
                          style: UIAlertActionStyle = .default,
                          preferred: Bool = false,

     - returns: Self
     */
    
    @discardableResult
    open func addCancel(_ title: String = "Cancel",
                          style: UIAlertActionStyle = .cancel,
                          preferred: Bool = false,
