anchor.diff:    Rethrow asRethrow() => this;
   
     accept(Visitor visitor) => visitor.visitRethrow(this);
  +
  +  accept1(Visitor1 visitor, arg) => visitor.visitRethrow(this, arg);
  +
     visitChildren(Visitor visitor) { }
  +
  +  visitChildren1(Visitor1 visitor, arg) { }
   
     Token getBeginToken() => throwToken;
     Token getEndToken() => endToken;
  
positive.code: 
    accept(Visitor visitor) => visitor.visitStringJuxtaposition(this);
  
    void visitChildren(Visitor visitor) {
      first.accept(visitor);
      second.accept(visitor);
    }
  
    Token getBeginToken() => first.getBeginToken();
  
    Token getEndToken() => second.getEndToken();
  
negative.code: 
    accept(Visitor visitor) => visitor.visitParenthesizedExpression(this);
  
    accept1(Visitor1 visitor, arg) {
      return visitor.visitParenthesizedExpression(this, arg);
    }
  
    visitChildren(Visitor visitor) {
      if (expression != null) expression.accept(visitor);
    }
  
    visitChildren1(Visitor1 visitor, arg) {
      if (expression != null) expression.accept1(visitor, arg);
    }
  
    Token getBeginToken() => beginToken;
  