code: func init() {
  	// This is needed to allow packages imported by 'server/auth' to make
  	// authenticated calls. They can't use GetRPCTransport directly, since they
  	// can't import 'server/auth' (it creates an import cycle).
  	internal.RegisterClientFactory(func(c context.Context, scopes []string) (*http.Client, error) {
  		var t http.RoundTripper
  		var err error
  		if len(scopes) == 0 {
  			t, err = GetRPCTransport(c, NoAuth)
  		} else {
  			t, err = GetRPCTransport(c, AsSelf, WithScopes(scopes...))
  		}
  		if err != nil {
  			return nil, err
  		}
  		return &http.Client{Transport: t}, nil
  	})
  }
docs: ////////////////////////////////////////////////////////////////////////////////
  // Internal stuff.