code: public function countBySiteIdAndLanguage($siteId, $language, $transverse)
      {
          $qa = $this->createAggregationQueryBuilderWithSiteIdAndLanguage($siteId, $language, $transverse);
  
          return $this->countDocumentAggregateQuery($qa);
      }
docs: @param string  $siteId
  @param string  $language
  @param boolean $transverse
  
  @return int