code: def fake_service_handler_factory(
      service_method: str, stream: bool
  ) -> Callable:
      def foo() -> bytes:
          return f"{'stream' if stream else 'unary'} call from {service_method}".encode()
  
      return foo
  
file_path: ray/python/ray/serve/tests/unit/test_grpc_util.py
imports: import pickle
  from typing import Callable
  import grpc
  import pytest
  from google.protobuf.any_pb2 import Any
  from ray import cloudpickle
  from ray.serve._private.grpc_util import DummyServicer, create_serve_grpc_server, gRPCServer
  from ray.serve._private.test_utils import FakeGrpcContext
  from ray.serve.grpc_util import RayServegRPCContext
label_desc: Use image node_id 1 for calling a global function with example usage: fake_service_handler_factory(service_method, stream) and returns: foo, unknown, str, service_method