code: def unregister_handler(
      fn_or_index: Union[int, Callable[[int, Any], None]]
  ):
      """Unregister a function by reference or index."""
      assert _handling_setup
      if isinstance(fn_or_index, int):
          _handler_functions.pop(fn_or_index)
      else:
          _handler_functions.remove(fn_or_index)
  
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 3 for calling a global function with example usage: unregister_handler(fn_or_index) without return types