public function getLukeMetaData($numberOfTerms = 0)
    {
        if (!isset($this->lukeData[$numberOfTerms])) {
            $lukeUrl = $this->_constructUrl(
                self::LUKE_SERVLET, ['numTerms' => $numberOfTerms, 'wt' => 'json', 'fl' => '*']
            );

            $this->lukeData[$numberOfTerms] = $this->_sendRawGet($lukeUrl);
        }

        return $this->lukeData[$numberOfTerms];
    }