code: func WithUser(c *container.Container) coci.SpecOpts {
  	return func(ctx context.Context, _ coci.Client, _ *containers.Container, s *coci.Spec) error {
  		uid, gid, additionalGids, err := getUser(c, c.Config.User)
  		if err != nil {
  			return err
  		}
  		s.Process.User.UID = uid
  		s.Process.User.GID = gid
  		s.Process.User.AdditionalGids = additionalGids
  		return nil
  	}
  }
docs: // WithUser sets the container's user