code: @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;
      }
docs: Provide the contribution of this part to the estimated 'fluffed' message size.
  Subclasses that wish to contribute to a quick guess at the length of a
  fluffed message should override this method, invoke their superclass and add on
  their own contribution.
  
  For this class, we should add an approximation of the size of the JMF
  JSMessageImpl which represents the JsPayloadSchema. If there is a body, we then
  call the subclass to add its specific size estimate.
  
  @return int A guesstimate of the fluffed size of the message