code: def get_ivector_extractor_id(ivector_dir=None):
      if ivector_dir is None:
          return None
      stdout_val = get_command_stdout(
          "steps/nnet2/get_ivector_id.sh {dir}".format(dir=ivector_dir)
      )
  
      if (stdout_val.strip() == "") or (stdout_val is None):
          return None
  
      return stdout_val.strip()
  
imports: from __future__ import print_function
  from __future__ import division
  import argparse
  import logging
  import math
  import os
  import subprocess
  import sys
  import threading
label_desc: Use image node_id 13 for calling a global function with example usage: get_ivector_extractor_id(ivector_dir) and returns: stdout_val, None, None