    public static function unzip($zip_file, $extract_path = null) {
        $zip = new \ZipArchive;
        if ($zip->open($zip_file)) {
            if (!$extract_path) {
                $path_info = pathinfo($zip_file);
                $extract_path = $path_info['dirname'].DS;
            }

            $zip->extractTo($extract_path);
            $zip->close();
            return true;

        } return false;
    }
