code: def test_set_request_protocol(serve_instance):
      """Test setting request protocol for a handle.
  
      When a handle is created, it's _request_protocol is undefined. When calling
      `_set_request_protocol()`, _request_protocol is set to the specified protocol.
      When chaining options, the _request_protocol on the new handle is copied over.
      When calling `_set_request_protocol()` on the new handle, _request_protocol
      on the new handle is changed accordingly, while _request_protocol on the
      original handle remains unchanged.
      """
  
      @serve.deployment
      def echo(name: str):
          return f"Hi {name}"
  
      handle = serve.run(echo.bind())
      assert (
          handle.handle_options._request_protocol
          == RequestProtocol.UNDEFINED
      )
  
      handle._set_request_protocol(RequestProtocol.HTTP)
      assert (
          handle.handle_options._request_protocol
          == RequestProtocol.HTTP
      )
  
      multiplexed_model_id = "fake-multiplexed_model_id"
      new_handle = handle.options(
          multiplexed_model_id=multiplexed_model_id
      )
      assert (
          new_handle.handle_options.multiplexed_model_id
          == multiplexed_model_id
      )
      assert (
          new_handle.handle_options._request_protocol
          == RequestProtocol.HTTP
      )
  
      new_handle._set_request_protocol(RequestProtocol.GRPC)
      assert (
          new_handle.handle_options._request_protocol
          == RequestProtocol.GRPC
      )
      assert (
          handle.handle_options._request_protocol
          == RequestProtocol.HTTP
      )
  
imports: import asyncio
  import concurrent.futures
  import threading
  import pytest
  import requests
  import ray
  from ray import serve
  from ray.serve._private.common import RequestProtocol
  from ray.serve._private.constants import SERVE_DEFAULT_APP_NAME
  from ray.serve._private.router import PowerOfTwoChoicesReplicaScheduler
  from ray.serve.exceptions import RayServeException
  from ray.serve.handle import DeploymentHandle, _HandleOptions
label_desc: Use image node_id 16 for calling a global function with example usage: test_set_request_protocol(serve_instance) and returns: str, name