protected function installFilesystem()
    {
        try {
            if(! ($this->getServiceManager()->get(FileSystemService::SERVICE_ID) instanceof FileSystemService)) {
                throw new InvalidService('Your service must be a oat\oatbox\filesystem\FileSystemService');
            }
        } catch(ServiceNotFoundException $e){
            $fileSystemService = new FileSystemService(array(FileSystemService::OPTION_FILE_PATH => $this->getOption('file_path')));
            $this->getServiceManager()->register(FileSystemService::SERVICE_ID, $fileSystemService);
        }
    }