code: public function findOneByLanguageAndVersion($contentId, $language, $version = null)
      {
          $qa = $this->createAggregationQueryWithContentIdAndLanguageAndVersion($contentId, $language, $version);
  
          return $this->singleHydrateAggregateQuery($qa);
      }
docs: @param string      $contentId
  @param string      $language
  @param string|null $version
  
  @return ContentInterface|null