anchor.diff:  import 'dart:async';
   import 'dart:html' as html;
   
  -import '../lib/services.dart' as services;
  +import 'enum.dart';
  +import 'services.dart' as services;
   import 'preferences.dart';
   
   final bool _INCLUDE_TYPES = true;
  
positive.code:   }
  
    void scrollIntoView() => _element.scrollIntoView();
  }
  
  abstract class OutlineTopLevelItem extends OutlineItem {
  
negative.code: 
      for (OutlineItem item in _outlineItems) {
        if (item.overlapsOffset(codeOffset)) {
          return item;
        }
      }
      return null;
    }
  
    OutlineItem _edgeItemInCodeOffsetRange(
        OffsetRange codeOffsetRange, {bool atBottom}) {
      if (_outlineItems == null) return null;
  
      Iterable<OutlineItem> searchSequence =
          atBottom ? _outlineItems.reversed : _outlineItems;
      for (OutlineItem item in searchSequence) {
        if (item.overlapsOffsetRange(codeOffsetRange)) {
          return item;
        }
      }
  