func (s *store) ttlOpts(ctx context.Context, ttl int64) ([]clientv3.OpOption, error) {
	if ttl == 0 {
		return nil, nil
	}
	id, err := s.leaseManager.GetLease(ctx, ttl)
	if err != nil {
		return nil, err
	}
	return []clientv3.OpOption{clientv3.WithLease(id)}, nil
}