anchor.diff:    Map<String, _YamlFileData> get _yamlAtCanonicalPathCache =>
         root.__yamlAtCanonicalPathCache;
   
  -  final ArgParser __argParser = ArgParser(usageLineLength: 80);
  +  final ArgParser __argParser = ArgParser(usageLineLength: _usageLineLength);
   
     ArgParser get argParser => root.__argParser;
   
  
positive.code: library dartdoc.dartdoc_options;
  
  import 'dart:async';
  import 'dart:io' show Platform;
  
  import 'package:analyzer/dart/element/element.dart';
  import 'package:analyzer/file_system/file_system.dart';
  
negative.code:           'dart.html',
            'dart.indexed_db',
            'dart.io',
            'dart.isolate',
            'dart.js',
            'dart.js_util',
            'dart.math',
  