public function servePrivateFile($key)
  {
    $File = $this->File->byKeyAndPublic($key , false)->first();

    if(!is_null($File))
    {
      return $this->serveFile($File->system_type, $File->system_route, $File->name);
    }

    return $this->Redirector->to($this->AppManager->getErrorPageUrl())->withError($this->Lang->get('decima-file::file-management.fileNotFound'));
  }