code: public function findPublishedByLanguageAndSiteId($language, $siteId)
      {
          $qa = $this->createAggregationQuery();
          $qa->match(
              array(
                  'siteId'=> $siteId,
                  'language'=> $language,
                  'status.publishedState' => true,
                  'nodeType' => NodeInterface::TYPE_DEFAULT
              )
          );
  
          return $this->hydrateAggregateQuery($qa);
      }
docs: @param string $language
  @param string $siteId
  
  @return ReadNodeInterface