anchor.diff:      if (parsedUri.hasScheme) {
         if (parsedUri.scheme == 'package') {
           return new AssetId(parsedUri.pathSegments.first,
  -            pathos.join('lib', pathos.joinAll(parsedUri.pathSegments.skip(1))));
  +            p.join('lib', p.joinAll(parsedUri.pathSegments.skip(1))));
         }
         throw new UnsupportedError(
             'Cannot resolve $uri; only "package" supported');
  
positive.code:   final String path;
  
    /// Gets the file extension of the asset, if it has one, including the ".".
    String get extension => pathos.extension(path);
  
    /// Creates a new [AssetId] at [path] within [package].
    ///
  
negative.code: }
  
  String _normalizePath(String path) {
    if (p.isAbsolute(path)) {
      throw new ArgumentError('Asset paths must be relative, but got "$path".');
    }
  
  