anchor.diff:  const String _API_PREFIX = '/api/dartservices/';
   const String _healthCheck = '/_ah/health';
   const String _readynessCheck = '/_ah/ready';
  +// Serve content for 4 hours, +- 1 hour.
  +final DateTime _serveUntil = DateTime.now()
  +    .add(Duration(hours: 3))
  +    .add(Duration(minutes: Random().nextInt(120)));
   
   final Logger _logger = Logger('gae_server');
   
  
positive.code:   }
  
    Future _processHealthRequest(io.HttpRequest request) async {
      if (!commonServerImpl.isHealthy) {
        _logger.severe('CommonServer is no longer healthy.'
            ' Intentionally failing health check.');
        request.response.statusCode = io.HttpStatus.internalServerError;
  
negative.code:   }
  
    Future _processReadynessRequest(io.HttpRequest request) async {
      if (!commonServerImpl.isRestarting &&
          DateTime.now().isBefore(_serveUntil)) {
        request.response.statusCode = io.HttpStatus.ok;
      } else {
        request.response.statusCode = io.HttpStatus.internalServerError;
  