protected function registerNativeFilesystem()
    {
        $this->app->singleton('files', function () {
            $config = $this->app['config'];
            $files = new Filesystem;
            $files->filePermissions = $config->get('system.filePermissions', null);
            $files->folderPermissions = $config->get('system.folderPermissions', null);
            $files->pathSymbols = [
                '$' => $config->get('system.extensionsPath', base_path('extensions')),
                '~' => base_path(),
            ];

            return $files;
        });
    }