protected function _processPrefixes($root)
    {
        foreach (array_keys($this->prefixes) as $prefix) {
            $controllers = $this->getControllerList(null, $prefix);
            $path = $this->rootNode . '/' . $prefix;
            $pathNode = $this->_checkNode($path, $prefix, $root->id);
            $this->foundACOs[$root->id][] = $prefix;
            if (isset($this->foundACOs[$pathNode->id])) {
                $this->foundACOs[$pathNode->id] += $this->_updateControllers($pathNode, $controllers, null, $prefix);
            } else {
                $this->foundACOs[$pathNode->id] = $this->_updateControllers($pathNode, $controllers, null, $prefix);
            }
        }
    }