code: def test_run_in_background():
      requests = []
      with IPCServer.run_in_background(requests.append) as server:
          send_request(server.port, 2)
          send_request(server.port, 3)
      assert requests == [2, 3]
  
imports: import contextlib
  import pickle
  import random
  import socket
  import sys
  import threading
  import time
  import psutil
  import pytest
  import retrying
  from fiftyone.service.ipc import IPCServer, send_request
  from fiftyone.service.util import find_processes_by_args, get_listening_tcp_ports, normalize_wrapper_process, send_ipc_message
label_desc: Use image node_id 11 for calling a global function with example usage: test_run_in_background() without return types