docs: public String getFullKey(String strSubKey)
      {
          String strReturnKey = strSubKey;
          if (strReturnKey == null)
              strReturnKey = Constant.BLANK;
          if (this.getMessageDataParent() instanceof MessageDataDesc)
          {    // Don't add for top level or above
              if (strReturnKey.length() > 0)
                  strReturnKey = '/' + strReturnKey;
              strReturnKey = this.getKey() + strReturnKey;
              strReturnKey = ((MessageDataDesc)this.getMessageDataParent()).getFullKey(strReturnKey);
          }
          return strReturnKey;
      }