code: def _generate_examples(book_train_file):
      """Yields text examples from the given book_train_file."""
      book_id = book_train_file.split("/")[-1].split("_")[0]
      with epath.Path(book_train_file).open() as f:
          for ind, line in enumerate(f):
              text = line.strip()
              if text:  # Skip empty lines.
                  key = f"book_{book_id}_ex_{ind}"
                  yield key, {"text": text, "book_id": book_id}
  
file_path: datasets/tensorflow_datasets/text/userlibri_lm_data/userlibri_lm_data.py
imports: import csv
  import os
  from etils import epath
  from tensorflow_datasets.core.utils.lazy_imports_utils import tensorflow
  import tensorflow_datasets.public_api
label_desc: Use image node_id 2 for calling a global function with example usage: _generate_examples(book_train_file) without return types