class_docstr: tracker for rabit
code: def __del__(self) -> None:
      if hasattr(self, "sock"):
          self.sock.close()
  
imports: import socket
  import struct
  import logging
  from threading import Thread
  import argparse
  import sys
  from typing import Dict, List, Tuple, Union, Optional, Set
label_desc: Use image node_id 2 for calling the RabitTracker obj's underlying member method code with example usage: obj.__del__() without return types