code: function sendStats() {
        var key = req[options.requestKey];
        key = key ? key + '.' : '';
  
        // Status Code
        var statusCode = res.statusCode || 'unknown_status';
        client.increment(key + 'status_code.' + statusCode);
  
        // Response Time
        var duration = new Date().getTime() - startTime;
        client.timing(key + 'response_time', duration);
  
        cleanup();
      }
docs: Function called on response finish that sends stats to statsd