code: def write_label_file(filename, num_labels):
      with tf.io.gfile.GFile(filename, "wb") as f:
          f.write(b"1" * 8)  # header
          f.write(make_labels(num_labels).tobytes())
  
file_path: datasets/tensorflow_datasets/testing/fake_data_generation/mnist.py
imports: import os
  from absl import app
  from absl import flags
  import numpy
  from tensorflow_datasets.core import utils
  from tensorflow_datasets.core.utils.lazy_imports_utils import tensorflow
  from tensorflow_datasets.testing import test_utils
label_desc: Use image node_id 6 for calling a global function with example usage: write_label_file(filename, num_labels) without return types