protected function _addTransformers(Model $model, Transit $transit, array $attachment) {
        if (empty($attachment['transforms'])) {
            return;
        }

        foreach ($attachment['transforms'] as $options) {
            $transformer = $this->_getTransformer($attachment, $options);

            if ($options['self']) {
                $transit->addSelfTransformer($transformer);
            } else {
                $transit->addTransformer($transformer);
            }
        }
    }