code: func (s *Stack) getServices() []string {
  	services := make([]string, len(s.Spec.Services))
  	for i, service := range s.Spec.Services {
  		services[i] = service.Name
  	}
  	sort.Strings(services)
  	return services
  }
docs: // getServices returns all the stack service names, sorted lexicographically