docs: @Override
      int guessFluffedSize() {
  
          // Get the contribution from the superclass(es)
          int total = super.guessFluffedSize();
  
          // Add the basic additional size for being a JMS message.
          total += FLUFFED_JMS_BASE_SIZE;
  
          // If there is a body in the message.....
          if (jmo.getPayloadPart().getChoiceField(JsPayloadAccess.PAYLOAD) != JsPayloadAccess.IS_PAYLOAD_EMPTY) {
  
              // Add in the extra overhead for having a fluffed body
              total += FLUFFED_PAYLOAD_BASE_SIZE;
  
              // And call the method to get the size of the fluffed data
              total += guessFluffedDataSize();
          }
  
          return total;
      }