anchor.diff:    return contents;
   }
   
  -List<String> _listLibraries(List<String> args) {
  -  var libraries = new List<String>();
  +List<Uri> _listLibraries(List<String> args) {
  +  var libraries = new List<Uri>();
     for (var arg in args) {
       var type = FileSystemEntity.typeSync(arg);
   
       if (type == FileSystemEntityType.FILE) {
         if (arg.endsWith('.dart')) {
  -        libraries.add(path.absolute(arg));
  +        libraries.add(new Uri.file(path.absolute(arg)));
           logger.info('Added to libraries: ${libraries.last}');
         }
       } else {
  
positive.code: 
  /// Analyzes set of libraries by getting a mirror system and triggers the
  /// documentation of the libraries.
  Future<MirrorSystem> getMirrorSystem(List<String> libraries,
      {String packageRoot, bool parseSdk: false}) {
    if (libraries.isEmpty) throw new StateError('No Libraries.');
    // Finds the root of SDK library based off the location of docgen.
  
negative.code:         ..showHints = false
          ..showWarnings = false)
            .diagnosticHandler;
    Uri libraryUri = new Uri.file(appendSlash(libraryRoot));
    Uri packageUri = null;
    if (packageRoot != null) {
      packageUri = new Uri.file(appendSlash(packageRoot));
    }
    return dart2js.analyze(libraries, libraryUri, packageUri,
        provider.readStringFromUri, diagnosticHandler,
        ['--preserve-comments', '--categories=Client,Server'])
        ..catchError((error) {
  