anchor.diff:    static final _evaluator = new ConstantEvaluator();
   
     final String _genFileName;
  +
     /// Contains generated `.gen.dart` code.
     final _genCode = new StringBuffer();
  +
     /// Contains rewritten `.ui.dart` code.
     final PrintStringWriter _uiCode;
   
  
positive.code:   @override
    AstNode visitClassDeclaration(ClassDeclaration node) {
      Annotation viewAnnotation = node.metadata.firstWhere(
          (Annotation ann) => ann.name.name == 'View', orElse: () => null);
      if (viewAnnotation != null) {
        var template =
            viewAnnotation.arguments.arguments.single.accept(_evaluator);
  
negative.code: final _formatter = new DartFormatter();
  String _fmt(String code) => _formatter.format(code);
  
  class LambdaTransformer extends Transformer implements DeclaringTransformer {
    LambdaTransformer.asPlugin();
  
    static const _EXTENSION = '.ui.dart';
  