code: function doPreBidderSync(type, url, bidder, done) {
    if (_s2sConfig.syncUrlModifier && typeof _s2sConfig.syncUrlModifier[bidder] === 'function') {
      const newSyncUrl = _s2sConfig.syncUrlModifier[bidder](type, url, bidder);
      doBidderSync(type, newSyncUrl, bidder, done)
    } else {
      doBidderSync(type, url, bidder, done)
    }
  }
docs: Modify the cookie sync url from prebid server to add new params.
  
  @param {string} type the type of sync, "image", "redirect", "iframe"
  @param {string} url the url to sync
  @param {string} bidder name of bidder doing sync for
  @param {function} done an exit callback; to signify this pixel has either: finished rendering or something went wrong