public CallbackRepository <T> InCallbacks()
        {
            var registeredSenderEvenArgs = RegisteredCallbacksRepository
                                           .Select(x => x.EventArgs)
                                           .ToList();

            return(new CallbackRepository <T>(Control, registeredSenderEvenArgs));
        }
        public CallbackRepository <T> InCallbacksOf(Control sender)
        {
            var registeredSenderEvenArgs = RegisteredCallbacksRepository
                                           .Where(x => x.Sender.UniqueID == sender.UniqueID)
                                           .Select(x => x.EventArgs)
                                           .ToList();

            return(new CallbackRepository <T>(sender, registeredSenderEvenArgs));
        }