anchor.diff:  
     Element get currentLibrary => libraryInfo.library;
   
  -
     void generateLibrary(
         Iterable<CompilationUnit> units, CheckerReporter reporter) {
  -
       out.write("""
   var $_libraryName;
   (function ($_libraryName) {
  
positive.code: 
    void _visitMapLiteralEntries(NodeList<MapLiteralEntry> nodes,
        {String separator}) {
  
      if (nodes == null) return;
      int size = nodes.length;
      if (size == 0) return;
  
negative.code:     currentClass = node;
  
      var name = node.name.name;
      out.write('class $name');
      _visitNode(node.typeParameters);
  
  