anchor.diff:     * Upgrades the connection to use TLS.
      */
     void _upgradeConnection(callback) {
  -    SecureSocket
  -        .secure(_connection,
  +    SecureSocket.secure(_connection,
               onBadCertificate: (_) => options.ignoreBadCertificate)
           .then((SecureSocket secured) {
         _connection = secured;
         _connection.listen(_onData, onError: _onSendController.addError);
  -      _connection.done
  -          .then((_) => _connectionOpen = false)
  -          .catchError(_onSendController.addError);
  +      _connection.done.catchError(_onSendController.addError);
         callback();
       });
     }
   
     void _actionGreeting(String message) {
  -    if (message.startsWith('220') == false) throw('Invalid greeting from server: $message');
  +    if (message.startsWith('220') == false)
  +      throw ('Invalid greeting from server: $message');
   
       _currentAction = _actionEHLO;
       sendCommand('EHLO ${options.name}');
  
positive.code:   bool _ignoreData = false;
  
    Socket _connection;
  
    bool _connectionOpen = false;
  
    /**
     * A list of supported authentication protocols.
  
negative.code:   }
  
    void _actionHELO(String message) {
      if (message.startsWith('2') == false)
        throw ('Invalid response for EHLO/HELO: $message');
  
      supportedAuthentications.add('LOGIN');
  
  