anchor.diff:  
     ast.Statement buildInScope(
         Statement node, LabelStack breakNode, LabelStack continueNode) {
  -    return new StatementBuilder(scope, breakNode, continueNode).build(node);
  +    var oldBreak = this.breakStack;
  +    var oldContinue = this.continueStack;
  +    breakStack = breakNode;
  +    continueStack = continueNode;
  +    var result = build(node);
  +    this.breakStack = oldBreak;
  +    this.continueStack = oldContinue;
  +    return result;
     }
   
     void buildBlockMember(Statement node, List<ast.Statement> output) {
  
positive.code: 
    List<ast.DartType> buildOptionalTypeArgumentList(TypeArgumentList node) {
      if (node == null) return null;
      return new TypeAnnotationBuilder(this).buildList(node.arguments);
    }
  
    List<ast.DartType> buildTypeArgumentList(TypeArgumentList node) {
      return new TypeAnnotationBuilder(this).buildList(node.arguments);
    }
  
    List<ast.TypeParameter> buildOptionalTypeParameterList(
  
negative.code: class TypeScope extends ReferenceScope {
    final Map<TypeParameterElement, ast.TypeParameter> localTypeParameters =
        <TypeParameterElement, ast.TypeParameter>{};
    TypeAnnotationBuilder _typeBuilder;
  
    TypeScope(ReferenceLevelLoader loader) : super(loader) {
      _typeBuilder = new TypeAnnotationBuilder(this);
    }
  
    String get location => '?';
  
  