code: def test_start_server(self, host):
      io = Interface(lambda x: x, "number", "number")
      io.favicon_path = None
      io.config = io.get_config_file()
      io.show_error = True
      io.flagging_callback.setup(gr.Number(), io.flagging_dir)
      io.auth = None
      io.host = host
  
      port = networking.get_first_available_port(
          networking.INITIAL_PORT_VALUE,
          networking.INITIAL_PORT_VALUE + networking.TRY_NUM_PORTS,
      )
      _, _, local_path, _, server = networking.start_server(
          io, server_port=port
      )
      url = urllib.parse.urlparse(local_path)
      assert url.scheme == "http"
      assert url.port == port
      server.close()
  
file_path: gradio/test/test_networking.py
imports: import os
  import urllib
  import warnings
  import pytest
  from fastapi.testclient import TestClient
  import gradio
  from gradio import Interface, networking
label_desc: Use image node_id 1 for calling the TestStartServer obj's underlying member method code with example usage: obj.test_start_server(host) without return types