code: func NewService(serviceName string, client *api.Client) (*Service, error) {
  	return NewServiceWithLogger(serviceName, client,
  		log.New(os.Stderr, "", log.LstdFlags))
  }
docs: // NewService creates and starts a Service. The caller must close the returned
  // service to free resources and allow the program to exit normally. This is
  // typically called in a signal handler.
  //
  // Caller must provide client which is already configured to speak to the local
  // Consul agent, and with an ACL token that has `service:write` privileges for
  // the service specified.