anchor.diff:    @override
     void visitConstructorFieldInitializer(ConstructorFieldInitializer node) {
       _recordDataForNode(
  -        'ConstructorFieldInitializer (expression)', node.expression);
  +        'ConstructorFieldInitializer (expression)', node.expression,
  +        allowedKeywords: expressionKeywords);
       super.visitConstructorFieldInitializer(node);
     }
   
  
positive.code: 
    @override
    void visitAssertInitializer(AssertInitializer node) {
      _recordDataForNode('AssertInitializer (condition)', node.condition);
      _recordDataForNode('AssertInitializer (message)', node.message);
      super.visitAssertInitializer(node);
    }
  
    @override
    void visitAssertStatement(AssertStatement node) {
      _recordDataForNode('AssertStatement (condition)', node.condition);
      _recordDataForNode('AssertStatement (message)', node.message);
      super.visitAssertStatement(node);
    }
  
    @override
    void visitAssignmentExpression(AssignmentExpression node) {
      _recordDataForNode('AssignmentExpression (rhs)', node.rightHandSide);
      var operatorType = node.operator.type;
      if (operatorType != TokenType.EQ &&
          operatorType != TokenType.QUESTION_QUESTION_EQ) {
  
negative.code:   @override
    void visitDefaultFormalParameter(DefaultFormalParameter node) {
      _recordDataForNode(
          'DefaultFormalParameter (defaultValue)', node.defaultValue,
          allowedKeywords: expressionKeywords);
      super.visitDefaultFormalParameter(node);
    }
  
    @override
    void visitDoStatement(DoStatement node) {
      _recordDataForNode('DoStatement (body)', node.body,
          allowedKeywords: statementKeywords);
      _recordDataForNode('DoStatement (condition)', node.condition,
          allowedKeywords: expressionKeywords);
      super.visitDoStatement(node);
    }
  
  