anchor.diff:  
   import 'package:args/args.dart';
   import 'package:collection/collection.dart';
  -import 'package:html/dom.dart' as dom;
  +import 'package:html/dom.dart';
   import 'package:html/parser.dart' show parseFragment;
   import 'package:markdown/markdown.dart' show markdownToHtml;
   import 'package:path/path.dart' as p;
  
positive.code:   } on FormatException catch (e) {
      stderr.writeln(e);
      print(parser.usage);
      exitCode = 64;
      return;
    }
  
  
negative.code: }
  
  /// Compare two DOM trees for equality.
  bool compareHtml(List<Element> expectedElements, List<Element> actualElements) {
    if (expectedElements.length != actualElements.length) {
      return false;
    }
  