code: function insertAds(adUnit, ads, adLoadedCallback) {
      var adContainers = page.getAdContainers(adUnit);
  
      if (!adContainers.length) {
          logger.error("No ad containers could be found. stopping insertion for adUnit " + adUnit.name);
          return []; //Ad can't be inserted
      }
      
      var adBuilder = new AdBuilder(ads);
  
      var beforeElement;
      var insertedAdElements = [];
      for (var i = 0; i < adContainers.length; i++) {
          var adContainer = adContainers[i];
          while ((beforeElement = adContainer.getNextElement()) !== null) {
              var adToInsert = adBuilder.createAdUnit(adUnit, adContainer.containerElement);
  
              if (adToInsert === null) {
                  //we ran out of ads.
                  break;
              }
  
              insertedAdElements.push(adToInsert);
              beforeElement.parentNode.insertBefore(adToInsert, beforeElement.nextSibling);
  
              // var elementDisplay = adToInsert.style.display || "block";
              //TODO: Why are we defaulting to block here?
              // adToInsert.style.display = elementDisplay;
              handleImageLoad(adToInsert, adLoadedCallback);
          }
      }
  
      return insertedAdElements;
  }
docs: Insert advertisements for the given ad unit on the page
  @param adUnit - The ad unit to insert advertisements for
  @param ads - Array of ads retrieved from OfferEngine
  @param adLoadedCallback - Callback to execute when the ads are fully loaded
  @returns {Array}