private function putRowInIndex(&$index, $metadataNamesToIndexBy, $row, $idSite, $period)
    {
        $currentLevel = & $index;

        foreach ($metadataNamesToIndexBy as $metadataName) {
            if ($metadataName == DataTableFactory::TABLE_METADATA_SITE_INDEX) {
                $key = $idSite;
            } elseif ($metadataName == DataTableFactory::TABLE_METADATA_PERIOD_INDEX) {
                $key = $period;
            } else {
                $key = $row[self::METADATA_CONTAINER_ROW_KEY][$metadataName];
            }

            if (!isset($currentLevel[$key])) {
                $currentLevel[$key] = array();
            }

            $currentLevel = & $currentLevel[$key];
        }

        $currentLevel = $row;
    }