code: def backward_kill_word(event: E) -> None:
      """
      Kills the word before point, using "not a letter nor a digit" as a word boundary.
      Usually bound to M-Del or M-Backspace.
      """
      unix_word_rubout(event, WORD=False)
  
imports: from __future__ import annotations
  from typing import Callable, TypeVar, Union, cast
  from prompt_toolkit.document import Document
  from prompt_toolkit.enums import EditingMode
  from prompt_toolkit.key_binding.key_bindings import Binding, key_binding
  from prompt_toolkit.key_binding.key_processor import KeyPress, KeyPressEvent
  from prompt_toolkit.keys import Keys
  from prompt_toolkit.layout.controls import BufferControl
  from prompt_toolkit.search import SearchDirection
  from prompt_toolkit.selection import PasteMode
  from .completion import display_completions_like_readline, generate_completions
label_desc: Use image node_id 31 for calling a global function with example usage: backward_kill_word(event) without return types