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