public function mapBackendRoutes()
    {
        $directory = __DIR__.'/../../routes/backend';
        if(is_dir($directory)) {
            $routeFiles = File::files($directory);
            \Route::group(
                [
                'middleware' => $this->middleware['backend'],
                ], function () use ($routeFiles) {
                    foreach ($routeFiles as $file) {
                        include $file;
                    }
                }
            );
        }
        return $this;
    }