code: public <T extends AmazonWebServiceRequest> T withRequestMetricCollector(RequestMetricCollector metricCollector) {
          setRequestMetricCollector(metricCollector);
          @SuppressWarnings("unchecked")
          T t = (T) this;
          return t;
      }
docs: Specifies a request level metric collector which takes precedence over the ones at the http
  client level and AWS SDK level.