public function mark_complete() {
        // Create record
        $this->timecompleted = time();

        // Save record
        if ($this->id) {
            $this->update();
        } else {
            $this->insert();
        }

        // Mark course completion record as started (if not already)
        $cc = array(
            'course'    => $this->course,
            'userid'    => $this->userid
        );
        $ccompletion = new completion_completion($cc);
        $ccompletion->mark_inprogress($this->timecompleted);
    }