code: function chainSerialPorts(clientPort, serverPort) {
      var observer = new OpenEventObserver(clientPort, serverPort);
  
      function serverPortWrite(data) {
          try {
              debug('writing to serverPort', data);
              if (! Buffer.isBuffer(data)) {
                  data = new Buffer(data);
              }
              serverPort.write(data);
          }
          catch (ex) {
              debug('error reading message', ex);
          }
      }
  
      function clientPortWrite(data) {
          try {
              debug('writing to clientPort', data);
              if (! Buffer.isBuffer(data)) {
                  data = new Buffer(data);
              }
              clientPort.write(data);
          }
          catch (ex) {
              debug('error reading message', ex);
          }
      }
  
      observer.once('open', function (data) {
          serverPort.on('data', function (data) {
              clientPortWrite(data);
          });
  
          clientPort.on('data', function (data) {
              serverPortWrite(data);
          });
      });
  }
docs: Helper function to chain Serial Port objects