anchor.diff:  part of esl;
   
   /**
  + * Transformer for converting raw bytes into [Packet] objects.
  + * Handles the low-level parsing of network traffic, or any other byte stream
  + * for that matter, stores them in a buffer and encapsulates them in [Packet]
  + * objects which the [Connection] then re-casts and injects into the
  + * appropriate steam - for instance event stream.
    *
  + * Can also be used standalone for parsing, for instance, packet dumps.
    */
   class PacketTransformer implements StreamTransformer<List<int>, Packet> {
     final StreamController<Packet> _controller = new StreamController<Packet>();
  
positive.code:               List<String> keyValuePair = headerLine.split(':');
  
                if (keyValuePair.length == 2) {
                  _currentPacket.addHeader(keyValuePair[0].trim(), keyValuePair[1].trim());
                } else {
                  this._controller.addError (new StateError ('Skipping invalid buffer: "${headerLine}"'));
                }
              }
            }
  
negative.code:     return _controller.stream;
    }
  
    /**
     * Callback for receiving and processing bytes.
     * Supports segmented transfers, such as TCP buffers.
     */
    void _onData(List<int> bytes) {
  
      for (int offset = 0; offset < bytes.length; offset++) {
  