code: def free_port():
      """Find free port using bind().
  
      There are some interval between finding this port and using it
      and the other process might catch the port by that time.
      Thus it is not guaranteed that the port is really empty.
  
      """
      with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
          sock.bind(("", 0))
          return sock.getsockname()[1]
  
imports: import dataclasses
  import os
  import socket
  from typing import Optional
  import torch
  import torch.distributed
label_desc: Use image node_id 5 for calling a global function with example usage: free_port() and returns: sock