code: def start_server(
      blocks: Blocks,
      server_name: str | None = None,
      server_port: int | None = None,
      ssl_keyfile: str | None = None,
      ssl_certfile: str | None = None,
      ssl_keyfile_password: str | None = None,
      app_kwargs: dict | None = None,
  ) -> tuple[str, int, str, App, Server]:
      """Launches a local server running the provided Interface
      Parameters:
          blocks: The Blocks object to run on the server
          server_name: to make app accessible on local network, set this to "0.0.0.0". Can be set by environment variable GRADIO_SERVER_NAME.
          server_port: will start gradio app on this port (if available). Can be set by environment variable GRADIO_SERVER_PORT.
          auth: If provided, username and password (or list of username-password tuples) required to access the Blocks. Can also provide function that takes username and password and returns True if valid login.
          ssl_keyfile: If a path to a file is provided, will use this as the private key file to create a local server running on https.
          ssl_certfile: If a path to a file is provided, will use this as the signed certificate for https. Needs to be provided if ssl_keyfile is provided.
          ssl_keyfile_password: If a password is provided, will use this with the ssl certificate for https.
          app_kwargs: Additional keyword arguments to pass to the gradio.routes.App constructor.
  
      Returns:
          port: the port number the server is running on
          path_to_local_server: the complete address that the local server can be accessed at
          app: the FastAPI app object
          server: the server object that is a subclass of uvicorn.Server (used to close the server)
      """
      if ssl_keyfile is not None and ssl_certfile is None:
          raise ValueError(
              "ssl_certfile must be provided if ssl_keyfile is provided."
          )
  
      server_name = server_name or LOCALHOST_NAME
      url_host_name = (
          "localhost" if server_name == "0.0.0.0" else server_name
      )
  
      # Strip IPv6 brackets from the address if they exist.
      # This is needed as http://[::1]:port/ is a valid browser address,
      # but not a valid IPv6 address, so asyncio will throw an exception.
      if server_name.startswith("[") and server_name.endswith("]"):
          host = server_name[1:-1]
      else:
          host = server_name
  
      app = App.create_app(blocks, app_kwargs=app_kwargs)
  
      server_ports = (
          [server_port]
          if server_port is not None
          else range(
              INITIAL_PORT_VALUE, INITIAL_PORT_VALUE + TRY_NUM_PORTS
          )
      )
  
      for port in server_ports:
          try:
              # The fastest way to check if a port is available is to try to bind to it with socket.
              # If the port is not available, socket will throw an OSError.
              s = socket.socket()
              s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
              # Really, we should be checking if (server_name, server_port) is available, but
              # socket.bind() doesn't seem to throw an OSError with ipv6 addresses, based on my testing.
              # Instead, we just check if the port is available on localhost.
              s.bind((LOCALHOST_NAME, port))
              s.close()
  
              # To avoid race conditions, so we also check if the port by trying to start the uvicorn server.
              # If the port is not available, this will throw a ServerFailedToStartError.
              config = uvicorn.Config(
                  app=app,
                  port=port,
                  host=host,
                  log_level="warning",
                  ssl_keyfile=ssl_keyfile,
                  ssl_certfile=ssl_certfile,
                  ssl_keyfile_password=ssl_keyfile_password,
              )
              reloader = None
              if GRADIO_WATCH_DIRS:
                  change_event = threading.Event()
                  app.change_event = change_event
                  reloader = SourceFileReloader(
                      app=app,
                      watch_dirs=GRADIO_WATCH_DIRS,
                      watch_module_name=GRADIO_WATCH_MODULE_NAME,
                      demo_name=GRADIO_WATCH_DEMO_NAME,
                      stop_event=threading.Event(),
                      change_event=change_event,
                  )
              server = Server(config=config, reloader=reloader)
              server.run_in_thread()
              break
          except (OSError, ServerFailedToStartError):
              pass
      else:
          raise OSError(
              f"Cannot find empty port in range: {min(server_ports)}-{max(server_ports)}. You can specify a different port by setting the GRADIO_SERVER_PORT environment variable or passing the `server_port` parameter to `launch()`."
          )
  
      if ssl_keyfile is not None:
          path_to_local_server = f"https://{url_host_name}:{port}/"
      else:
          path_to_local_server = f"http://{url_host_name}:{port}/"
  
      return server_name, port, path_to_local_server, app, server
  
imports: from __future__ import annotations
  import os
  import socket
  import threading
  import time
  import warnings
  from functools import partial
  from typing import TYPE_CHECKING
  import httpx
  import uvicorn
  from uvicorn.config import Config
  from gradio.exceptions import ServerFailedToStartError
  from gradio.routes import App
  from gradio.tunneling import Tunnel
  from gradio.utils import SourceFileReloader, watchfn
label_desc: Use image node_id 3 for calling a global function with example usage: start_server(blocks, server_name, server_port, ssl_keyfile, ssl_certfile, ssl_keyfile_password, app_kwargs) and returns: server_name,  port,  path_to_local_server,  app,  server