code: func containsLimit(execs []*tipb.Executor) bool {
  	for _, exec := range execs {
  		if exec.Limit != nil {
  			return true
  		}
  	}
  	return false
  }
docs: // containsLimit tests if the execs contains Limit because we do not know whether `Limit` has consumed all of its' source,
  // so the feedback may not be accurate.