Inheritance: implements IteratorAggregate, implements Countable, implements Symfony\Component\Serializer\Normalizer\NormalizableInterface
 private function addToDirectory(FeatureDirectory $directory, $feature)
 {
     if (false === strpos($feature, '/')) {
         $directory->addEntry(new FeatureFile($directory, $feature));
         return;
     }
     list($name, $rest) = explode('/', $feature, 2);
     $this->addToDirectory($directory->getOrCreateDirectory($name), $rest);
 }