code: function dispatchImps(bidRequests, refererInfo) {
    let secure = (refererInfo && refererInfo.referer.indexOf('https:') === 0);
    return bidRequests.map(bidRequest => buildImp(bidRequest, secure))
      .reduce((acc, curr, index) => {
        let bidRequest = bidRequests[index];
        let zoneId = bidRequest.params.zoneId;
        let host = bidRequest.params.host;
        acc[host] = acc[host] || {};
        acc[host][zoneId] = acc[host][zoneId] || [];
        acc[host][zoneId].push(curr);
        return acc;
      }, {});
  }
docs: Dispatch impressions by ad network host and zone