code: def get_unused_port():
      """Returns a (hopefully) unused port number.
  
      This function does not guarantee that the port it returns is available,
      only that a series of get_unused_port calls in a single process return
      distinct ports.
  
      .. deprecated::
         Use bind_unused_port instead, which is guaranteed to find an unused port.
      """
      global _next_port
      port = _next_port
      _next_port = _next_port + 1
      return port
  
imports: from __future__ import absolute_import, division, print_function
  from tornado.log import gen_log, app_log
  from tornado.stack_context import ExceptionStackContext
  from tornado.util import raise_exc_info, basestring_type, PY3
  import functools
  import inspect
  import logging
  import os
  import re
  import signal
  import socket
  import sys
label_desc: Use image node_id 1 for calling a global function with example usage: get_unused_port() and returns: port