code: func NewService(ctx context.Context, opts ...option.ClientOption) (*Service, error) {
  	scopesOption := option.WithScopes(
  		"https://www.googleapis.com/auth/userinfo.email",
  	)
  	// NOTE: prepend, so we don't override user-specified scopes.
  	opts = append([]option.ClientOption{scopesOption}, opts...)
  	client, endpoint, err := htransport.NewClient(ctx, opts...)
  	if err != nil {
  		return nil, err
  	}
  	s, err := New(client)
  	if err != nil {
  		return nil, err
  	}
  	if endpoint != "" {
  		s.BasePath = endpoint
  	}
  	return s, nil
  }
docs: // NewService creates a new Service.