Alex\BehatLauncher\Behat\FeatureDirectory::addEntry PHP Method

    public function addEntry($entry)
    {
        if (!$entry instanceof FeatureDirectory && !$entry instanceof FeatureFile) {
            throw new \InvalidArgumentException(sprintf('Expected FeatureDirectory or FeatureFile, got "%s".', is_object($entry) ? get_class($entry) : gettype($entry)));
        }
        $this->entries[] = $entry;
        return $this;
    }

 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);
 }