docstr: Find a preview PNG for a given path (without extension) and call link_preview on it.
code: def find_preview(self, path):
      """
      Find a preview PNG for a given path (without extension) and call link_preview on it.
      """
  
      potential_files = sum(
          [
              [path + "." + ext, path + ".preview." + ext]
              for ext in allowed_preview_extensions()
          ],
          [],
      )
  
      for file in potential_files:
          if os.path.isfile(file):
              return self.link_preview(file)
  
      return None
  
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 12 for calling the ExtraNetworksPage obj's underlying member method code with example usage: obj.find_preview(path) and returns: None, self