public function getJSON()
    {
        global $CFG;
        $PDOX = $this->launch->pdox;

        $stmt = $PDOX->queryDie(
            "SELECT json FROM {$CFG->dbprefix}lti_result
                WHERE result_id = :RID",
            array(':RID' => $this->id)
        );
        $row = $stmt->fetch(\PDO::FETCH_ASSOC);
        return $row['json'];
    }