code: public void setArchiveFormat(String format)
    {
      if (format.endsWith(".gz")) {
        _archiveFormat = format.substring(0, format.length() - ".gz".length());
        _archiveSuffix = ".gz";
      }
      else if (format.endsWith(".zip")) {
        _archiveFormat = format.substring(0, format.length() - ".zip".length());
        _archiveSuffix = ".zip";
      }
      else {
        _archiveFormat = format;
        _archiveSuffix = "";
      }
    }
docs: Sets the archive name format