anchor.diff:  
   class SerialPort {
   
  -
  +  static const int _EOL = 10;
     static const List<int> AUTHORIZED_BAUDATE_SPEED =  const [50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 230400, 4000000];
   
     final String portname;
  
positive.code:     return completer.future;
    }
  
    Stream<String> get onRead {
      StreamController<String> controller = new StreamController();
      _onReadControllers.add(controller);
  
negative.code:   RawReceivePort _readPort  = null;
  
    int _ttyFd = -1;
  
    final StringBuffer _lineBuffer = new StringBuffer();
  
  
    SerialPort(this.portname, {this.baudrate : 9600}){
      if(!AUTHORIZED_BAUDATE_SPEED.contains(baudrate)){
  