code: def checkSerial(self):
          
          for item in self.rxSerial(self._TUN._tun.mtu):
              # print("about to send: {0}".format(item))
              try:
                  self._TUN._tun.write(item)
              except pytun.Error as error:
                  print("pytun error writing: {0}".format(item))
                  print(error)
docs: Check the serial port for data to write to the TUN adapter.