anchor.diff:      assert(libraryNode == null,
           "encountered library with duplicated name: $compositeLibraryName");
       infoNodesByName[compositeLibraryName] = newLibrary;
  -    outputInfo.add(newLibrary);
     }
   
     void makeFunction(FunctionInfo functionInfo) {
  
positive.code:   /// filename of the outputUnit.
    String compositeName(String name, String outputUnitName) =>
        "$name/$outputUnitName";
  
    /// Mapping between the name of a [Info] object and the corresponding
    /// [vm.ProgramInfoNode] object.
    final Map<String, vm.ProgramInfoNode> infoNodesById = {};
  
    /// Mapping between the composite name of a package and the corresponding
    /// [vm.ProgramInfoNode] objects of [vm.NodeType.packageNode].
  
negative.code: library dart2js_info.bin.to_devtools_format;
  
  import 'dart:convert';
  import 'dart:io' as io;
  
  import 'package:args/command_runner.dart';
  import 'package:dart2js_info/info.dart';
  import 'package:dart2js_info/src/io.dart';
  import 'package:dart2js_info/src/util.dart' show longName, libraryGroupName;
  import 'package:vm_snapshot_analysis/program_info.dart' as vm;
  import 'package:vm_snapshot_analysis/treemap.dart';
  import 'usage_exception.dart';
  
  /// Command that converts a `--dump-info` JSON output into a format ingested by Devtools.
  