protected function _commandSubscribe($command)
    {
        $entity = $this->getController()->getItem();

        $action = ($entity->subscribed(get_viewer()) ? 'unsubscribe' : 'subscribe');
        $label = AnTranslator::_('LIB-AN-ACTION-'.strtoupper($action));

        $command->append(array('label' => $label))
            ->href($entity->getURL())
            ->class('action-'.$action)
            ->setAttribute('data-action', $action);
    }