protected function createAggregationQueryBuilderWithSiteIdAndLanguage($siteId, $language)
    {
        $qa = $this->createAggregationQueryBuilderWithSiteId($siteId);
        $qa->match(array('language' => $language));

        return $qa;
    }
protected function createAggregationQueryBuilderWithSiteIdAndLanguage($siteId, $language)
    {
        $qa = $this->createAggregationQueryBuilderWithSiteId($siteId);
        $qa->match(array('language' => $language));

        return $qa;
    }
@param string $siteId
@param string $language

@return Stage