anchor.diff:  
     // TODO rename sendString
     // TODO send with List<int>
  -  // TODO Future
     Future<bool> send(String data){
       // TODO check OPEN
       var completer = new Completer<bool>();
  
positive.code: 
  class SerialPort {
  
    // TODO : Review state
    static const int CONNECTING = 0;
    static const int OPEN = 1;
    static const int CLOSED = 3;
    static const int CLOSING = 2;
  
    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;
    final int baudrate;
  
    // TODO fail state ?
    int _state;
  
    int _ttyFd = -1;
  
    SerialPort(this.portname, {this.baudrate : 9600}){
      _state = CONNECTING;
      if(!AUTHORIZED_BAUDATE_SPEED.contains(baudrate)){
        throw new ArgumentError("Unknown baudrate speed=$baudrate");
      }
  
negative.code:       if (result != null) {
          // TODO return value ?
          _ttyFd = -1;
          completer.complete(true);
        } else {
          completer.completeError("Unexpected error");
  