code: @Override
      public ListMetricsResult listMetrics(ListMetricsRequest request) {
          request = beforeClientExecution(request);
          return executeListMetrics(request);
      }
docs: <p>
  List the specified metrics. You can use the returned metrics with <a>GetMetricData</a> or
  <a>GetMetricStatistics</a> to obtain statistical data.
  </p>
  <p>
  Up to 500 results are returned for any one call. To retrieve additional results, use the returned token with
  subsequent calls.
  </p>
  <p>
  After you create a metric, allow up to fifteen minutes before the metric appears. Statistics about the metric,
  however, are available sooner using <a>GetMetricData</a> or <a>GetMetricStatistics</a>.
  </p>
  
  @param listMetricsRequest
  @return Result of the ListMetrics operation returned by the service.
  @throws InternalServiceException
  Request processing has failed due to some unknown error, exception, or failure.
  @throws InvalidParameterValueException
  The value of an input parameter is bad or out-of-range.
  @sample AmazonCloudWatch.ListMetrics
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/monitoring-2010-08-01/ListMetrics" target="_top">AWS API
  Documentation</a>