code: public function findPublishedVersion($contentId, $language)
      {
          $qa = $this->createAggregationQueryWithLanguageAndPublished($language);
  
          $qa->match(array('contentId' => $contentId));
  
          return $this->singleHydrateAggregateQuery($qa);
      }
docs: @param string $contentId
  @param string $language
  
  @return ContentInterface