anchor.diff:    path = path.replaceAll(r"\", "/");
   
     // Collapse "." and "..".
  -  return pathos.posix.normalize(path);
  +  return p.posix.normalize(path);
   }
  
positive.code:   /// Returns a new [AssetId] with the same [package] and [path] as this one
    /// but with file extension [newExtension].
    AssetId changeExtension(String newExtension) =>
        new AssetId(package, pathos.withoutExtension(path) + newExtension);
  
    @override
    String toString() => "$package|$path";
  
negative.code:   final String path;
  
    /// Gets the file extension of the asset, if it has one, including the ".".
    String get extension => p.extension(path);
  
    /// Creates a new [AssetId] at [path] within [package].
    ///
  