anchor.diff:  
   import 'package:front_end/src/fasta/kernel/body_builder.dart' show BodyBuilder;
   
  -import 'package:front_end/src/fasta/scanner.dart' show scanString;
  -
   import 'package:front_end/src/fasta/type_inference/type_inference_engine.dart'
       show TypeInferenceEngine;
   
  
positive.code: 
  import 'package:front_end/src/fasta/parser.dart' show MemberKind, Parser;
  
  import 'package:front_end/src/scanner/token.dart' show Token;
  
  import 'package:front_end/src/fasta/source/source_library_builder.dart'
      show SourceLibraryBuilder;
  
negative.code:         createListener(builder, memberScope, builder.isInstanceMember);
  
      if (!isTopLevel) {
        listener.classDeclaration = astFactory.classDeclaration(
          null,
          null,
          null,
          new Token(Keyword.CLASS, 0),
          astFactory.simpleIdentifier(
              new StringToken.fromString(TokenType.IDENTIFIER, 'Cx', 6)),
          null,
          null,
          null,
  