public function addChildren($dirPathname)
    {
        $files = new \RecursiveIteratorIterator(
            new \RecursiveDirectoryIterator($dirPathname, \FilesystemIterator::SKIP_DOTS),
            \RecursiveIteratorIterator::SELF_FIRST
        );

        foreach($files as $info)
        {
            $relativePathname = $this->subtractBasedir($info->getPathname(), $dirPathname);
            #echo sprintf("%s\n", $relativePathname);

            if ($info->isDir())
            {
                $this->zip->addEmptyDir($relativePathname);
            }
            else {
                $this->zip->addFile($info->getPathname(), $relativePathname);
            }
        }
    }