code: def test_unset_fields_schema_to_deployment_ray_actor_options():
      # Ensure unset fields are excluded from ray_actor_options
  
      @serve.deployment(
          num_replicas=3,
          route_prefix="/hello",
          ray_actor_options={},
      )
      def f():
          pass
  
      deployment = schema_to_deployment(deployment_to_schema(f))
      deployment.set_options(
          func_or_class="ray.serve.tests.test_schema.global_f"
      )
  
      # Serve will set num_cpus to 1 if it's not set.
      assert len(deployment.ray_actor_options) == 1
      assert deployment.ray_actor_options["num_cpus"] == 1
  
imports: import copy
  import json
  import logging
  import sys
  from typing import Dict, List, Optional, Union
  import pytest
  from ray import serve
  from ray._private.pydantic_compat import ValidationError
  from ray.serve.config import AutoscalingConfig
  from ray.serve.deployment import deployment_to_schema, schema_to_deployment
  from ray.serve.schema import DeploymentSchema, LoggingConfig, RayActorOptionsSchema, ServeApplicationSchema, ServeDeploySchema, ServeInstanceDetails
  from ray.serve.tests.common.remote_uris import TEST_DEPLOY_GROUP_PINNED_URI, TEST_MODULE_PINNED_URI
  from ray.util.accelerators.accelerators import NVIDIA_TESLA_P4, NVIDIA_TESLA_V100
label_desc: Use image node_id 7 for calling a global function with example usage: test_unset_fields_schema_to_deployment_ray_actor_options() without return types