code: def file_server(request: pytest.FixtureRequest) -> SimpleWebServer:
      server = SimpleWebServer()
      server.start()
      request.addfinalizer(server.stop)
      return server
  
file_path: bokeh/tests/support/plugins/file_server.py
imports: from __future__ import annotations
  import logging
  import os
  import threading
  from http.server import BaseHTTPRequestHandler, HTTPServer
  from pathlib import Path
  from typing import Any
  from urllib.request import urlopen
  import pytest
label_desc: Use image node_id 1 for calling a global function with example usage: file_server(request) and returns: server