anchor.diff:    /// * 'explanation': The Mustache context for the tooltip explaining why the
     ///   content in this region was modified.
     List<Map> _computeRegions(UnitInfo unitInfo) {
  +    String unitDir = _directoryContaining(unitInfo);
       String content = unitInfo.content;
       List<Map> regions = [];
       int previousOffset = 0;
  
positive.code: 
    /// Return the content of the file with navigation links and anchors added.
    String _computeNavigationContent(UnitInfo unitInfo) {
      String content = unitInfo.content;
      OffsetMapper mapper = unitInfo.offsetMapper;
      Map<int, String> openInsertions = {};
  
negative.code:   /// Creates an output object for the given library info.
    InstrumentationRenderer(this.unitInfo, this.migrationInfo, this.pathMapper);
  
    /// Return the path context used to manipulate paths.
    path.Context get pathContext => migrationInfo.pathContext;
  
    /// Builds an HTML view of the instrumentation information in [unitInfo].
    String render() {
      // TODO(brianwilkerson) Restore syntactic highlighting.
  