anchor.diff:    }
   
     void _writeDQT(_ByteBuffer out) {
  -    out.writeUint16(0xFFDB); // marker
  +    _writeMarker(out, _Jpeg.M_DQT);
       out.writeUint16(132); // length
       out.writeByte(0);
       for (int i = 0; i < 64; i++) {
  
positive.code:   }
  
    List<int> encode(Image image) {
      _ByteBuffer out = new _ByteBuffer();
  
      // Add JPEG headers
      out.writeUint16(0xFFD8); // SOI
      _writeAPP0(out);
      _writeDQT(out);
      _writeSOF0(out, image.width, image.height);
      _writeDHT(out);
      _writeSOS(out);
  
      // Encode 8x8 macroblocks
      int DCY = 0;
      int DCU = 0;
      int DCV = 0;
  
      out.resetBits();
  
      int width = image.width;
      int height = image.height;
  
negative.code:   }
  
    void _writeDHT(_ByteBuffer out) {
      _writeMarker(out, _Jpeg.M_DHT);
      out.writeUint16(0x01A2); // length
  
      out.writeByte(0); // HTYDCinfo
  