public function getDirectoryListing($path='/')
    {
        // 1. find out what is mounted on this path
        $listing = array();
        foreach($this->nodes as $node) {
            $mp = $node->getMountPoint();
            if ((dirname($mp) == $path) && ($path != '/')) {
                $listing[] = basename($mp)."/";
            }
            if (strncmp($path, $mp, strlen($mp)) === 0) {
                $listing = array_merge($listing, $node->getDirectoryListing($path));
            }
        }
        
        return $listing;
    }