code: def signal_handler(signal, frame):
      logging.info("Stop copying")
      sys.exit(0)
  
file_path: dgl/tools/copy_files.py
imports: import argparse
  import copy
  import json
  import logging
  import os
  import signal
  import stat
  import subprocess
  import sys
label_desc: Use image node_id 4 for calling a global function with example usage: signal_handler(signal, frame) without return types