code: def get_free_tcp_port():
      with socketserver.TCPServer(("localhost", 0), None) as s:
          free_port = s.server_address[1]
          return free_port
  
imports: import contextlib
  import json
  import os
  import socket
  import socketserver
  import sys
  from typing import Iterable
  from typing import List
  from typing import Optional
  from typing import Union
  import docker
  from pydantic import BaseModel
  from ...abstract_node import AbstractNode
  from ...custom_worker.builder import CustomWorkerBuilder
  from ...custom_worker.config import DockerWorkerConfig
  from ...node.credentials import SyftVerifyKey
  from ...types.uid import UID
  from ...util.util import get_queue_address
  from ..response import SyftError
  from .worker_image import SyftWorkerImage
  from .worker_image_stash import SyftWorkerImageStash
  from .worker_pool import ContainerSpawnStatus
  from .worker_pool import SyftWorker
  from .worker_pool import WorkerHealth
  from .worker_pool import WorkerOrchestrationType
  from .worker_pool import WorkerStatus
label_desc: Use image node_id 4 for calling a global function with example usage: get_free_tcp_port() and returns: free_port