code: public byte[] sendSubmitSmResp(OutputStream os, int sequenceNumber,
              String messageId) throws PDUStringException, IOException {
          byte[] b = pduComposer.submitSmResp(sequenceNumber, messageId);
          writeAndFlush(os, b);
          return b;
      }
docs: /*
  (non-Javadoc)
  
  @see org.jsmpp.PDUSender#sendSubmitSmResp(java.io.OutputStream, int,
  java.lang.String)