docs: function (adUnitSettings) {
          var containers = adUnitSettings.containers;
  
          var adContainers = [];
  
          for (var i = 0; i < containers.length; i++) {
              var container = containers[i];
  
              var containerXPath = container.xPath;
              var adContainerElements = xPath(containerXPath);
  
              if (!adContainerElements.length) {
                  logger.warn("Ad container with xPath: \"" + containerXPath + "\" could not be found on page");
                  continue;
              }
  
              if (adContainerElements.length > 1) {
                  logger.warn("Ad container with xPath:  \"" + containerXPath + "\" has multiple matches");
              }
  
              adContainers.push(new AdContainer(container, adContainerElements[0]));
          }
  
          return adContainers;
      }