code: def test_serve_namespace(ray_start_stop):
      """Check that the driver can interact with Serve using the Python API."""
  
      config = {
          "applications": [
              {
                  "name": "my_app",
                  "import_path": "ray.serve.tests.test_config_files.world.DagNode",
              }
          ],
      }
  
      print("Deploying config.")
      deploy_config_multi_app(config, SERVE_HEAD_URL)
      wait_for_condition(
          lambda: requests.post("http://localhost:8000/").text
          == "wonderful world",
          timeout=15,
      )
      print("Deployments are live and reachable over HTTP.\n")
  
      ray.init(address="auto", namespace="serve")
      my_app_status = serve.status().applications["my_app"]
      assert (
          len(my_app_status.deployments) == 2
          and my_app_status.deployments["f"] is not None
      )
      print(
          "Successfully retrieved deployment statuses with Python API."
      )
      print("Shutting down Python API.")
      serve.shutdown()
      ray.shutdown()
  
imports: import copy
  import grpc
  import re
  import os
  import sys
  from typing import Dict
  import pytest
  import requests
  import ray
  from ray import serve
  from ray._private.test_utils import wait_for_condition
  import ray._private.ray_constants
  from ray.util.state import list_actors
  from ray.serve._private.constants import SERVE_NAMESPACE
  from ray.serve.tests.conftest import *
  from ray.tests.conftest import *
  from ray._private.test_utils import generate_system_config_map
  from ray.serve.schema import ServeInstanceDetails, HTTPOptionsSchema
  from ray.serve._private.common import ApplicationStatus, DeploymentStatus, DeploymentStatusTrigger, ReplicaState, ProxyStatus
  from ray.serve.generated import serve_pb2, serve_pb2_grpc
label_desc: Use image node_id 9 for calling a global function with example usage: test_serve_namespace(ray_start_stop) without return types