docs: private static String calculateMessageBodyMd5(String messageBody) {
          if (log.isDebugEnabled()) {
              log.debug("Message body: " + messageBody);
          }
          byte[] expectedMd5;
          try {
              expectedMd5 = Md5Utils.computeMD5Hash(messageBody.getBytes(UTF8));
          } catch (Exception e) {
              throw new AmazonClientException("Unable to calculate the MD5 hash of the message body. " + e.getMessage(),
                      e);
          }
          String expectedMd5Hex = BinaryUtils.toHex(expectedMd5);
          if (log.isDebugEnabled()) {
              log.debug("Expected  MD5 of message body: " + expectedMd5Hex);
          }
          return expectedMd5Hex;
      }