code: def utt2spk_str(self, speaker_id):
      return "{} {}".format(self.utt_id(), speaker_id)
  
imports: import argparse
  import os
  import re
  import sys
  from collections import namedtuple
  import yaml
label_desc: Use image node_id 6 for calling the JKACLabel obj's underlying member method code with example usage: obj.utt2spk_str(speaker_id) and returns: str