code: func (s *server) Tail(c context.Context, req *logdog.TailRequest) (*logdog.GetResponse, error) {
  	r := logdog.GetRequest{
  		Project: req.Project,
  		Path:    req.Path,
  		State:   req.State,
  	}
  	return s.getImpl(c, &r, true)
  }
docs: // Tail returns the last log entry for a given log stream.