protected function getProgressBar(InputInterface $input)
    {
        $progress = parent::getProgressBar($input);
        if (!$progress) {
            return null;
        }

        /** @var Dispatcher $eventDispatcher */
        $eventDispatcher = $this->getService('event_dispatcher');
        $eventDispatcher->addListener(
            'transformer.transformation.post',
            function () use ($progress) {
                $progress->advance();
            }
        );

        return $progress;
    }