code: func (r *RoleBindingBuilder) SAs(namespace string, serviceAccountNames ...string) *RoleBindingBuilder {
  	for _, saName := range serviceAccountNames {
  		r.RoleBinding.Subjects = append(r.RoleBinding.Subjects, Subject{Kind: ServiceAccountKind, Namespace: namespace, Name: saName})
  	}
  	return r
  }
docs: // SAs adds the specified service accounts as the subjects of the
  // RoleBinding.