code: def _determine_target_loop():
      """We determine target loop based on whether RAY_SERVE_DEBUG_MODE is enabled:
  
      - RAY_SERVE_DEBUG_MODE=0 (default): we use "uvloop" (Cython) providing
                                high-performance, native implementation of the event-loop
  
      - RAY_SERVE_DEBUG_MODE=1: we fall back to "asyncio" (pure Python) event-loop
                                implementation that is considerably slower than "uvloop",
                                but provides for easy access to the source implementation
      """
      if RAY_SERVE_DEBUG_MODE:
          return "asyncio"
      else:
          return "uvloop"
  
imports: import asyncio
  import json
  import logging
  import os
  import pickle
  import socket
  import time
  import uuid
  from abc import ABC, abstractmethod
  from typing import Any, Callable, Dict, Generator, List, Optional, Tuple, Type
  import grpc
  import starlette.routing
  import uvicorn
  from starlette.datastructures import MutableHeaders
  from starlette.middleware import Middleware
  from starlette.types import Receive
  import ray
  from ray import serve
  from ray._private.utils import get_or_create_event_loop
  from ray.actor import ActorHandle
  from ray.exceptions import RayActorError, RayTaskError
  from ray.serve._private.common import EndpointInfo, EndpointTag, NodeId, RequestProtocol
  from ray.serve._private.constants import DEFAULT_LATENCY_BUCKET_MS, DEFAULT_UVICORN_KEEP_ALIVE_TIMEOUT_S, PROXY_MIN_DRAINING_PERIOD_S, RAY_SERVE_HTTP_PROXY_CALLBACK_IMPORT_PATH, SERVE_CONTROLLER_NAME, SERVE_LOGGER_NAME, SERVE_MULTIPLEXED_MODEL_ID, SERVE_NAMESPACE
  from ray.serve._private.grpc_util import DummyServicer, create_serve_grpc_server
  from ray.serve._private.http_util import MessageQueue, convert_object_to_asgi_messages, receive_http_body, set_socket_reuse_port, validate_http_proxy_callback_return
  from ray.serve._private.logging_utils import access_log_msg, configure_component_cpu_profiler, configure_component_logger, configure_component_memory_profiler, get_component_logger_file_path
  from ray.serve._private.long_poll import LongPollClient, LongPollNamespace
  from ray.serve._private.proxy_request_response import ASGIProxyRequest, HandlerMetadata, ProxyRequest, ResponseGenerator, ResponseHandlerInfo, ResponseStatus, gRPCProxyRequest
  from ray.serve._private.proxy_response_generator import ProxyResponseGenerator
  from ray.serve._private.proxy_router import EndpointRouter, LongestPrefixRouter, ProxyRouter
  from ray.serve._private.usage import ServeUsageTag
  from ray.serve._private.utils import call_function_from_import_path
  from ray.serve.config import gRPCOptions
  from ray.serve.generated.serve_pb2 import HealthzResponse, ListApplicationsResponse
  from ray.serve.generated.serve_pb2_grpc import add_RayServeAPIServiceServicer_to_server
  from ray.serve.handle import DeploymentHandle
  from ray.serve.schema import LoggingConfig
  from ray.util import metrics
label_desc: Use image node_id 2 for calling a global function with example usage: _determine_target_loop() and returns: str, str