code: def _start_update_server(auth_token: str) -> AccumulatorServer:
      """Start a TCP server to receive accumulator updates in a daemon thread, and returns it"""
      server = AccumulatorServer(
          ("localhost", 0), _UpdateRequestHandler, auth_token
      )
      thread = threading.Thread(target=server.serve_forever)
      thread.daemon = True
      thread.start()
      return server
  
imports: import sys
  import select
  import struct
  import socketserver
  import threading
  from typing import Callable, Dict, Generic, Tuple, Type, TYPE_CHECKING, TypeVar, Union
  from pyspark.serializers import read_int, CPickleSerializer
  from pyspark.errors import PySparkRuntimeError
label_desc: Use image node_id 2 for calling a global function with example usage: _start_update_server(auth_token) and returns: server