anchor.diff:  import 'dart:convert';
   import 'dart:io';
   
  +import 'package:args/args.dart';
   import 'package:intl/intl.dart';
   import 'package:path/path.dart' as path;
  -
  -/// Whether to report all error messages (true) or attempt to filter out some
  -/// known false positives (false).
  -///
  -/// Set this to false locally if you want to address Flutter-specific issues.
  -const bool kVerbose = true; // please leave this as true on Travis
   
   const String kDocRoot = 'dev/docs/doc';
   
  
positive.code: /// in your path. It requires that 'flutter' has been run previously. It uses
  /// the version of Dart downloaded by the 'flutter' tool in this repository and
  /// will crash if that is absent.
  Future<Null> main(List<String> args) async {
    // If we're run from the `tools` dir, set the cwd to the repo root.
    if (path.basename(Directory.current.path) == 'tools')
      Directory.current = Directory.current.parent.parent;
  
negative.code:     '--category-order', 'flutter,Dart Core,flutter_test,flutter_driver',
      '--show-warnings',
      '--auto-include-dependencies',
    ]);
  
    // Explicitly list all the packages in //flutter/packages/* that are
    // not listed 'nodoc' in their pubspec.yaml.
    for (String libraryRef in libraryRefs(diskPath: true)) {
      dartdocArgs.add('--include-external');
      dartdocArgs.add(libraryRef);
    }
  
    process = await Process.start(
      pubExecutable,
      dartdocArgs,
      workingDirectory: 'dev/docs',
      environment: pubEnvironment,
    );
    printStream(process.stdout, prefix: args['json'] ? '' : 'dartdoc:stdout: ',
      filter: args['verbose'] ? const <Pattern>[] : <Pattern>[
        new RegExp(r'^generating docs for library '), // unnecessary verbosity
        new RegExp(r'^pars'), // unnecessary verbosity
      ],
    );
    printStream(process.stderr, prefix: args['json'] ? '' : 'dartdoc:stderr: ',
      filter: args['verbose'] ? const <Pattern>[] : <Pattern>[
        new RegExp(r'^[ ]+warning: generic type handled as HTML:'), // https://github.com/dart-lang/dartdoc/issues/1475
        new RegExp(r'^ warning: .+: \(.+/\.pub-cache/hosted/pub.dartlang.org/.+\)'), // packages outside our control
      ],
    );
  