def restore_from_checkpoint(sess, saver):
  """Restore model from checkpoint.

  Args:
    sess: Session.
    saver: Saver for restoring the checkpoint.

  Returns:
    bool: Whether the checkpoint was found and restored
  """
  ckpt = tf.train.get_checkpoint_state(FLAGS.checkpoint_dir)
  if not ckpt or not ckpt.model_checkpoint_path:
    tf.logging.info('No checkpoint found at %s', FLAGS.checkpoint_dir)
    return False

  saver.restore(sess, ckpt.model_checkpoint_path)
  return True