code: def gen_dummy_data_dir(
      data_dir, num_spk, num_utt_per_spk, feat_len=100, feat_dim=40
  ):
      """Generate a dummy data directory and return its meta."""
      os.makedirs(data_dir, exist_ok=True)
  
      meta = kaldi_dir.KaldiMetaData()
      feats = {}
      vads = {}
      for spk_idx in range(num_spk):
          for utt_idx in range(num_utt_per_spk):
              spk = str(spk_idx)
              utt = "%s_%d" % (spk, utt_idx)
              utt_meta = kaldi_dir.Utt()
              feat_mat = np.ones((feat_len, feat_dim), dtype="float32")
              feats[utt] = feat_mat
              utt_meta.featlen = feat_len
              vad_mat = np.ones((feat_len,), dtype="float32")
              vads[utt] = vad_mat
              utt_meta.spk = spk
              meta.utts[utt] = utt_meta
      meta.collect_spks_from_utts()
      meta.dump(data_dir, True)
  
      feats_ark_path = os.path.join(data_dir, "feats.ark")
      feats_scp_path = os.path.join(data_dir, "feats.scp")
      kaldiio.save_ark(
          feats_ark_path, feats, scp=feats_scp_path, text=True
      )
      vad_ark_path = os.path.join(data_dir, "vad.ark")
      vad_scp_path = os.path.join(data_dir, "vad.scp")
      kaldiio.save_ark(vad_ark_path, vads, scp=vad_scp_path, text=True)
  
      loaded_meta = kaldi_dir.KaldiMetaData()
      loaded_meta.load(data_dir)
      return loaded_meta
  
file_path: delta/delta/utils/kaldi/kaldi_dir_utils.py
imports: import os
  from random import Random
  from absl import logging
  import numpy
  import kaldiio
  from delta.utils.kaldi import kaldi_dir
label_desc: Use image node_id 2 for calling a global function with example usage: gen_dummy_data_dir(data_dir, num_spk, num_utt_per_spk, feat_len, feat_dim) and returns: loaded_meta