code: func required(s *status.Status) (bool, string) {
  	if s.Group == status.EndorserClientStatus && s.Code == status.ConnectionFailed.ToInt32() {
  		return true, peerURLFromConnectionFailedStatus(s.Details)
  	}
  	return false, ""
  }
docs: // required decides whether the given status error warrants a greylist
  // on the peer causing the error