code: public static void main(String argv[]) throws Exception {
      DnsMonitorSecurityManager.setTheManager();
      AvatarZKShell shell = null;
  
      shell = new AvatarZKShell();
      int res;
      try {
        res = ToolRunner.run(shell, argv);
      } finally {
        shell.close();
      }
      System.exit(res);
    }
docs: main() has some simple utility methods