class_docstr: Librispeech dataset.
class_docstr_tok: ["Librispeech","dataset","."]
code: def _populate_metadata(self, dirs: Iterable[epath.Path]):
      # All dirs contain the same metadata.
      directory = list(dirs)[0]
      self.info.metadata["speakers"] = self._read_metadata_file(
          directory / "LibriSpeech/SPEAKERS.TXT",
          ["speaker_id", "gender", "subset", "minutes", "name"],
      )
      self.info.metadata["chapters"] = self._read_metadata_file(
          directory / "LibriSpeech/CHAPTERS.TXT",
          [
              "chapter_id",
              "speaker_id",
              "minutes",
              "subset",
              "project_id",
              "book_id",
              "chapter_title",
              "project_title",
          ],
      )
  
file_path: datasets/tensorflow_datasets/datasets/librispeech/librispeech_dataset_builder.py
imports: from __future__ import annotations
  import os
  from typing import Iterable, List
  from etils import epath
  import numpy
  from tensorflow_datasets.core.utils.lazy_imports_utils import tensorflow
  import tensorflow_datasets.public_api
label_desc: Use image node_id 2 for calling the Builder obj's underlying member method code with example usage: obj._populate_metadata(dirs) without return types