code: def test_deploy_nullify_route_prefix(serve_instance, prefixes):
      # With multi dags support, dag driver will receive all route
      # prefix when route_prefix is "None", since "None" will be converted
      # to "/" internally.
      # Note: the expose http endpoint will still be removed for internal
      # dag node by setting "None" to route_prefix
      @serve.deployment
      def f(*args):
          return "got me"
  
      for prefix in prefixes:
          dag = f.options(route_prefix=prefix).bind()
          handle = serve.run(dag)
          assert (
              requests.get("http://localhost:8000/f").status_code == 200
          )
          assert (
              requests.get("http://localhost:8000/f").text == "got me"
          )
          assert handle.remote().result() == "got me"
  
imports: import functools
  import os
  import sys
  import threading
  import time
  from concurrent.futures.thread import ThreadPoolExecutor
  from typing import Dict
  import pytest
  import requests
  import ray
  from ray import serve
  from ray._private.pydantic_compat import ValidationError
  from ray._private.test_utils import SignalActor, wait_for_condition
  from ray.serve._private.common import ApplicationStatus
  from ray.serve._private.logging_utils import get_component_log_file_name, get_serve_logs_dir
  from ray.util.state import list_actors
label_desc: Use image node_id 1 for calling a global function with example usage: test_deploy_nullify_route_prefix(serve_instance, prefixes) and returns: str