code: public void defaultChecker(CommsByteBuffer buffer, short exceptionCode)
        throws SIErrorException
     {
        if (exceptionCode != CommsConstants.SI_NO_EXCEPTION)
        {
           throw new SIErrorException(buffer.getException(con));
        }
     }
docs: The default checker. Should always be called last after all the checkers.
  @param buffer
  @param exceptionCode
  @throws SIErrorException if the exception code is <strong>not</strong>
  the enumerated value for "throw no exception".