public static function AddStringPersistentListener(unityEvent:
UnityEventBase,
call: UnityAction<string>,
argument: string):
        void;
      
                  public static void AddStringPersistentListener(UnityEventBase unityEvent,
UnityAction<string> call,
string argument);
    
                  public static
      def AddStringPersistentListener(unityEvent as UnityEventBase,
 call as UnityAction<string>,
 argument as string)
      
        as void