anchor.diff:    int _cacheYStride;
     int _cacheUVStride;
   
  -  Data.Uint8List tmpY;
  -  Data.Uint8List tmpU;
  -  Data.Uint8List tmpV;
  +  Data.Uint8List _tmpY;
  +  Data.Uint8List _tmpU;
  +  Data.Uint8List _tmpV;
   
     VP8List _y;
     VP8List _u;
  
positive.code:     final int yEnd = mbY + mbH;
      final int uvW = (mbW + 1) >> 1;
      final int stride = webp.width * 4;
      //WebPUpsampleLinePairFunc upsample = WebPUpsamplers[p->output->colorspace];
      //const uint8_t* top_u = p->tmp_u;
      //const uint8_t* top_v = p->tmp_v;
  
      if (y == 0) {
        // First line is special cased. We mirror the u/v samples at boundary.
        upsample(cur_y, NULL, cur_u, cur_v, cur_u, cur_v, dst, NULL, mb_w);
      } else {
        // We can finish the left-over line from previous call.
        upsample(p->tmp_y, curY, topU, topV, curU, curV,
                 dst - stride, dst, mbW);
        ++numLinesOut;
      }*/
  
      // Loop over each output pairs of row.
      /*for (; y + 2 < y_end; y += 2) {
  
negative.code:     return true;
    }
  
    int _clip8(int v) {
      return ((v & ~YUV_MASK2) == 0) ? (v >> YUV_FIX2) : (v < 0) ? 0 : 255;
    }
  
  