let instance = null; //singleton class BUCServer { constructor(config) { if (!instance) { this.config = Object.assign({}, config); this.config.tempDownloadDir = `${config.tempDir}/download`; fs.ensureDirSync(this.config.tempDownloadDir); this.down = new FileDownloader(config.maxUploadFileSize); instance = this; } return instance; } async main() { } } module.exports = BUCServer;