code: def _configure_saver(checkpoint_dir, checkpoint_interval):
    
    saver = tf.train.Saver()
    return tf.train.CheckpointSaverHook(
        checkpoint_dir=checkpoint_dir,
        save_steps=checkpoint_interval,
        saver=saver)
docs: Returns a tf.train.CheckpointSaverHook for autosaving checkpoints.