docs: function zip(contentsZip, publicKey, signature) {
    debug(`zip(): start`);
    return new Promise((res, rej) => {
      const output = new streamBuffers.WritableStreamBuffer();
      const zipFile = new ZipFile();
      output.on("finish", () => {
        debug(`zip(): output finish event`);
        res(output.getContents());
      });
      zipFile.outputStream.pipe(output);
      zipFile.addBuffer(contentsZip, "contents.zip");
      zipFile.addBuffer(publicKey, "PUBKEY");
      zipFile.addBuffer(signature, "SIGNATURE");
      zipFile.end(finalSize => {
        debug(`zip(): ZipFile end event: finalSize ${finalSize} bytes`);
      });
    });
  }