anchor.diff:    if (n.endsWith('.gif')) {
       return new GifDecoder();
     }
  +  if (n.endsWith('.tif') || n.endsWith('.tiff')) {
  +    return new TiffDecoder();
  +  }
     return null;
   }
   
  
positive.code: List<int> encodeGifAnimation(Animation anim) {
    return new GifEncoder().encodeAnimation(anim);
  }
  
negative.code:     return webp;
    }
  
    TiffDecoder tiff = new TiffDecoder();
    if (tiff.isValidFile(bytes)) {
      return tiff;
    }
  
    return null;
  }
  
  