public function col_indicators($log) {
        $indicatorclasses = json_decode($log->indicators);
        $indicators = array();
        foreach ($indicatorclasses as $indicatorclass) {
            $indicator = \core_analytics\manager::get_indicator($indicatorclass);
            if ($indicator) {
                $indicators[] = $indicator->get_name();
            } else {
                debugging('Can\'t load ' . $indicatorclass . ' indicator', DEBUG_DEVELOPER);
            }
        }
        return '<ul><li>' . implode('</li><li>', $indicators) . '</li></ul>';
    }