code: def on_script_unloaded(callback):
      """register a function to be called before the script is unloaded. Any hooks/hijacks/monkeying about that
      the script did should be reverted here"""
  
      add_callback(callback_map["callbacks_script_unloaded"], callback)
  
imports: import inspect
  import os
  from collections import namedtuple
  from typing import Optional, Any
  from fastapi import FastAPI
  from gradio import Blocks
  from modules import errors, timer
label_desc: Use image node_id 42 for calling a global function with example usage: on_script_unloaded(callback) without return types