def METHOD_NAME(directory, images_file, labels_file):
  """Download and parse MNIST dataset."""
  images_file = download(directory, images_file)
  labels_file = download(directory, labels_file)
  check_image_file_header(images_file)
  check_labels_file_header(labels_file)
  def decode_image(image):
    # Normalize from [0, 255] to [0.0, 1.0]
    image = tf.decode_raw(image, tf.uint8)
    image = tf.cast(image, tf.float32)
    image = tf.reshape(image, [784])
    return image / 255.0
  def decode_label(label):
    label = tf.decode_raw(label, tf.uint8)  # tf.string -> [tf.uint8]
    label = tf.reshape(label, [])  # label is a scalar
    return tf.to_int32(label)
  images = tf.data.FixedLengthRecordDataset(
      images_file, 28 * 28, header_bytes=16).map(decode_image)
  labels = tf.data.FixedLengthRecordDataset(
      labels_file, 1, header_bytes=8).map(decode_label)
  return tf.data.Dataset.zip((images, labels))