code: function defaultOptions(opts) {
      opts.bucketSize = opts.bucketSize || 20;
      opts.concurrency = opts.concurrency || 3;
      opts.expireTime = opts.expireTime || 60 * 60 * 24;
      opts.refreshTime = opts.refreshTime || 60 * 60;
      opts.replicateTime = opts.replicateTime || 60 * 60;
      opts.republishTime = opts.republishTime || 60 * 60 * 24;
  }
docs: Fill `opts` with the default options if needed.