code: def register_handler(fn: Callable[[int, Any], None]):
      """Register a function to be used as a signal handler.
  
      The function will be placed on top of the stack."""
      assert _handling_setup
      _handler_functions.insert(0, fn)
  
file_path: ray/release/ray_release/signal_handling.py
imports: import signal
  import sys
  from typing import Any, Callable, List, Union
  from ray_release.logger import logger
label_desc: Use image node_id 2 for calling a global function with example usage: register_handler(fn) without return types