protected function updateUsers()
    {
        $user_id = $this->getAuthUserId();
        if (!($user_id > 0)) {
            return;
        }

        if (!$this->isDirty('updated_by')) {
            $this->updated_by = $user_id;
        }

        if (!$this->exists && !$this->isDirty('created_by')) {
            $this->created_by = $user_id;
        }
    }