public static function check_lti_id($linkid, $course, $toolproxy) {
        global $DB;
        // Check if lti type is zero or not (comes from a backup).
        $sqlparams1 = array();
        $sqlparams1['linkid'] = $linkid;
        $sqlparams1['course'] = $course;
        $ltiactivity = $DB->get_record('lti', array('id' => $linkid, 'course' => $course));
        if ($ltiactivity->typeid == 0) {
            $tool = lti_get_tool_by_url_match($ltiactivity->toolurl, $course);
            if (!$tool) {
                $tool = lti_get_tool_by_url_match($ltiactivity->securetoolurl, $course);
            }
            return (($tool) && ($toolproxy == $tool->toolproxyid));
        } else {
            $sqlparams2 = array();
            $sqlparams2['linkid'] = $linkid;
            $sqlparams2['course'] = $course;
            $sqlparams2['toolproxy'] = $toolproxy;
            $sql = 'SELECT lti.*
                      FROM {lti} lti
                INNER JOIN {lti_types} typ ON lti.typeid = typ.id
                     WHERE lti.id = ?
                           AND lti.course = ?
                           AND typ.toolproxyid = ?';
            return $DB->record_exists_sql($sql, $sqlparams2);
        }
    }