$messagecontact = new \stdClass();
        $messagecontact->userid = $student_id; // user
        $messagecontact->contactid = $teacher->id; // user
        $messagecontact->timecreated = time();
        $messagecontact->id = $DB->insert_record('message_contacts', $messagecontact);

        $eventparams = [
            'objectid' => $messagecontact->id,
            'userid' => $student_id,
            'relateduserid' => $teacher->id,
            'context' => \context_user::instance($student_id)
        ];
        $event = \core\event\message_contact_added::create($eventparams);
        $event->add_record_snapshot('message_contacts', $messagecontact);
        $event->trigger();