code: def open_tunnel(
      addr,
      server,
      keyfile=None,
      password=None,
      paramiko=None,
      timeout=60,
  ):
      """Open a tunneled connection from a 0MQ url.
  
      For use inside tunnel_connection.
  
      Returns
      -------
  
      (url, tunnel) : (str, object)
          The 0MQ url that has been forwarded, and the tunnel object
      """
  
      lport = select_random_ports(1)[0]
      transport, addr = addr.split("://")
      ip, rport = addr.split(":")
      rport = int(rport)
      if paramiko is None:
          paramiko = sys.platform == "win32"
      if paramiko:
          tunnelf = paramiko_tunnel
      else:
          tunnelf = openssh_tunnel
  
      tunnel = tunnelf(
          lport,
          rport,
          server,
          remoteip=ip,
          keyfile=keyfile,
          password=password,
          timeout=timeout,
      )
      return "tcp://127.0.0.1:%i" % lport, tunnel
  
file_path: catboost/contrib/python/pyzmq/py3/zmq/ssh/tunnel.py
imports: import atexit
  import os
  import re
  import signal
  import socket
  import sys
  import warnings
  from getpass import getpass, getuser
  from multiprocessing import Process
label_desc: Use image node_id 6 for calling a global function with example usage: open_tunnel(addr, server, keyfile, password, paramiko, timeout) and returns: unknown,  tunnel