public function getUserGroupManager()
    {
        if ($this->userGroupManager != null) {
            return $this->userGroupManager;
        }

        $this->userGroupManager = new UserGroupManager($this->options, $this->getUserService(), $this->getContentService(), $this->getContentTypeService());

        if ($this->logger) {
            $this->userGroupManager->setLogger($this->logger);
        }

        return $this->userGroupManager;
    }