class_docstr: Kaldi dir meta data IO test
docstr: test dump and load data 
code: def test_gen_dummy_data(self):
      """test dump and load data"""
      num_spk = 5
      num_utt_per_spk = 3
      meta = gen_dummy_meta(num_spk, num_utt_per_spk)
      self.assertEqual(len(meta.spks), num_spk)
  
file_path: delta/delta/utils/kaldi/kaldi_dir_test.py
imports: import os
  from absl import logging
  import delta.compat
  from delta.utils.kaldi import kaldi_dir
  from delta.utils.kaldi.kaldi_dir_utils import gen_dummy_meta
label_desc: Use image node_id 4 for calling the KaldiDirTest obj's underlying member method code with example usage: obj.test_gen_dummy_data() without return types