code: public Object get(String strKey)
      {
          if (this.getMessageFieldDesc(strKey) != null)
              return this.getMessageFieldDesc(strKey).get();
          return this.getNative(strKey);
      }
docs: Do any of the conversion that has to be done for all message types.
  Typically overidden to return correctly converted data.
  @param trxMessage The raw internal trx message.
  @return The new Internal message with additional/refined data.