code: private long getTotalBytes(String bucketName,
                                 AmazonCloudWatch client) {
          long totalBytes = 0;
          totalBytes += getMetricData(bucketName,
                                      "BucketSizeBytes",
                                      "StandardStorage",
                                      client);
          totalBytes += getMetricData(bucketName,
                                      "BucketSizeBytes",
                                      "StandardIAStorage",
                                      client);
          totalBytes += getMetricData(bucketName,
                                      "BucketSizeBytes",
                                      "ReducedRedundancyStorage",
                                      client);
          return totalBytes;
      }
docs: Gets the total byte count for all storage types and combines them to
  produce a single stored bytes value
  
  @param bucketName
  @return