code: def register_page(page):
      """registers extra networks page for the UI; recommend doing it in on_before_ui() callback for extensions"""
  
      extra_pages.append(page)
      allowed_dirs.clear()
      allowed_dirs.update(
          set(
              sum(
                  [
                      x.allowed_directories_for_previews()
                      for x in extra_pages
                  ],
                  [],
              )
          )
      )
  
imports: import functools
  import os.path
  import urllib.parse
  from pathlib import Path
  from modules import shared, ui_extra_networks_user_metadata, errors, extra_networks
  from modules.images import read_info_from_image, save_image_with_geninfo
  import gradio
  import json
  import html
  from fastapi.exceptions import HTTPException
  from modules.generation_parameters_copypaste import image_from_url_text
  from modules.ui_components import ToolButton
label_desc: Use image node_id 3 for calling a global function with example usage: register_page(page) without return types