private function registerController(string $controllerClassName)
    {
        $controllerAnnotation = $this->getControllerAnnotation($controllerClassName);

        if ($controllerAnnotation instanceof Controller) {
            $controllerName = trim($controllerClassName, "\\");
            $this->app["$controllerName"] = function (Application $app) use ($controllerName) {
                return new $controllerName($app);
            };

            $this->processClassAnnotation($controllerAnnotation);
        }
    }