docs: def distorted_inputs():
    """Construct distorted input for CIFAR training using the Reader ops.
  
    Returns:
      images: Images. 4D tensor of [batch_size, IMAGE_SIZE, IMAGE_SIZE, 3] size.
      labels: Labels. 1D tensor of [batch_size] size.
  
    Raises:
      ValueError: If no data_dir
    """
    if not FLAGS.data_dir:
      raise ValueError('Please supply a data_dir')
    data_dir = os.path.join(FLAGS.data_dir, 'cifar-10-batches-bin')
    images, labels = cifar10_input.distorted_inputs(data_dir=data_dir,
                                                    batch_size=FLAGS.batch_size)
    if FLAGS.use_fp16:
      images = tf.cast(images, tf.float16)
      labels = tf.cast(labels, tf.float16)
    return images, labels