code: func (b *cmdRunBase) ModifyContext(c context.Context) context.Context {
  	c = logging.SetLevel(gologger.StdConfig.Use(c), logging.Debug)
  	opts, err := b.authFlags.Options()
  	if err != nil {
  		logging.Errorf(c, "%s", err.Error())
  		panic("failed to get auth options")
  	}
  	http, err := auth.NewAuthenticator(c, auth.OptionalLogin, opts).Client()
  	if err != nil {
  		logging.Errorf(c, "%s", err.Error())
  		panic("failed to get authenticator")
  	}
  	srv, err := compute.New(http)
  	if err != nil {
  		logging.Errorf(c, "%s", err.Error())
  		panic("failed to get GCE API service")
  	}
  	return context.WithValue(c, &key, srv)
  }
docs: // ModifyContext returns a new context.
  // Configures logging and embeds the GCE API service.
  // Implements cli.ContextModificator.