protected function findFile(): void
    {
        $path = Application::getInstance()->getPath();
        $file = "$path/modules/{$this->module}/controllers/{$this->controller}.php";

        if (!file_exists($file)) {
            throw new ControllerException("Controller file not found '{$this->module}/{$this->controller}'", 404);
        }

        $this->file = $file;
    }