init(options) {
      this.options = options;
      this.sessionId = "";
      this.synoToken = "";
      if (this.options.address.substr(-1) == "/") {
        this.options.address = this.options.address.substr(0, this.options.address.length - 1);
      }
    }
@see https://global.download.synology.com/download/Document/DeveloperGuide/Synology_Download_Station_Web_API.pdf
@backport https://github.com/pt-plugins/PT-Plugin-Plus/blob/48c2d42a1d05c129c0abbbecf653b1b7d88a8a8e/src/resource/btClients/src/clients/synologyDownloadStation.ts