anchor.diff:  import 'package:dart2js_info/info.dart';
   import 'package:dart2js_info/src/io.dart';
   import 'package:vm_snapshot_analysis/treemap.dart';
  -import 'package:dart2js_info/src/util.dart' show libraryGroupName;
  +import 'package:dart2js_info/src/util.dart';
   import 'package:vm_snapshot_analysis/program_info.dart' as vm;
   
   /// Command that converts a `--dump-info` JSON output into a format ingested by Devtools.
  
positive.code:   void makeClass(ClassInfo classInfo) {
      Info? parent = classInfo.parent;
      if (parent != null) {
        vm.ProgramInfoNode? parentNode = infoNodesByName[parent.name];
        vm.ProgramInfoNode newClass = program.makeNode(
            name: classInfo.name,
            parent: parentNode!,
            type: vm.NodeType.classNode);
        newClass.size = classInfo.size;
        parentNode.children[newClass.name] = newClass;
  
negative.code:     info.classTypes.forEach(visitClassType);
      info.typedefs.forEach(makeTypedef);
      info.typedefs.forEach(visitTypedef);
      return infoNodesByName[info.name] ??
          infoNodesByName[unnamedLibraries[info]]!;
    }
  
    @override
  