anchor.diff:  // BSD-style license that can be found in the LICENSE file.
   
   library docgen.models.indexable;
  +
  +import 'dart:collection';
   
   import 'package:markdown/markdown.dart' as markdown;
   
  
positive.code: /// issue. The second level map is indexed by owner docName for faster lookup.
  /// Why two levels of lookup? Speed, man. Speed.
  final Map<String, Map<String, Indexable>> _mirrorToDocgen =
      new Map<String, Map<String, Indexable>>();
  
  Iterable<Indexable> get allIndexables =>
      _mirrorToDocgen.values.expand((map) => map.values);
  
negative.code:     var mirrorQualifiedName = dart2js_util.qualifiedNameOf(this.mirror);
  
      var map = _mirrorToDocgen.putIfAbsent(mirrorQualifiedName,
          () => new HashMap<String, Indexable>());
  
      var added = false;
      map.putIfAbsent(owner.docName, () {
  