anchor.diff:    var scriptDir = path.dirname(Platform.script.toFilePath());
     var introduction = includeSdk ? '' : options['introduction'];
   
  -  var pubScript = options['sdk'] != null ? 
  +  var pubScript = options['sdk'] != null ?
         path.join(options['sdk'], 'bin', 'pub') : 'pub';
   
  -  var dartBinary = options['sdk'] != null ? 
  +  var dartBinary = options['sdk'] != null ?
         path.join(options['sdk'], 'bin', 'dart') : 'dart';
   
  -  docgen(_files,
  +  var excludedLibraries = options['exclude-lib'];
  +  if(excludedLibraries == null) excludedLibraries = [];
  +
  +  docgen(files,
         packageRoot: options['package-root'],
         outputToYaml: !options['json'],
         includePrivate: options['include-private'],
  
positive.code: 
  import 'package:args/args.dart';
  import 'package:logging/logging.dart';
  
  import '../lib/docgen.dart';
  import 'package:path/path.dart' as path;
  
  List<String> excludedLibraries = [];
  
  /**
   * The files/directories that we're being asked to document.
   */
  List<String> _files;
  
  /**
   * Analyzes Dart files and generates a representation of included libraries,
  
negative.code:         if (verbose) Logger.root.level = Level.FINEST;
        });
    parser.addFlag('json', abbr: 'j',
        help: 'Outputs to JSON. If negated, outputs to YAML. '
          'If --append is used, it takes the file-format of the previous '
          'run stated in library_list.json, ignoring the flag.',
        negatable: true, defaultsTo: true);
    parser.addFlag('include-private',
        help: 'Flag to include private declarations.', negatable: false);
  