code: def _add_utt2spk(self, utt_id, spk):
      self.utt2spk.append("{} {}".format(utt_id, spk))
  
file_path: espnet/egs2/dsing/asr1/local/data_prep.py
imports: import argparse
  import hashlib
  import json
  import re
  from os import listdir, makedirs
  from os.path import exists, isfile, join
label_desc: Use image node_id 6 for calling the DataSet obj's underlying member method code with example usage: obj._add_utt2spk(utt_id, spk) without return types