public function addBundle($bundle)
    {
        $bundle = $this->getBundleString($bundle);
        // not root bundle
        if (strpos($this->getKernal(), $bundle) === false) {
            $bundles = $this->getBundles();
            if (!in_array($bundle, $bundles)) {
                $bundles[] = $bundle;
                $this->setBundles($bundles);
            }
        }
    }