code: public byte[] dataSmResp(int sequenceNumber, String messageId,
              OptionalParameter... optionalParameters) throws PDUStringException {
          StringValidator.validateString(messageId, StringParameter.MESSAGE_ID);
  
          PDUByteBuffer buf = new PDUByteBuffer(SMPPConstant.CID_DATA_SM_RESP, 0,
                  sequenceNumber);
          buf.append(messageId);
  
          return buf.toBytes();
      }
docs: /*
  (non-Javadoc)
  
  @see org.jsmpp.util.PDUComposer#dataSmResp(int, java.lang.String,
  org.jsmpp.bean.OptionalParameter[])