anchor.diff:  
     accept(Visitor visitor) => visitor.visitNewExpression(this);
   
  +  accept1(Visitor1 visitor, arg) => visitor.visitNewExpression(this, arg);
  +
     visitChildren(Visitor visitor) {
       if (send != null) send.accept(visitor);
  +  }
  +
  +  visitChildren1(Visitor1 visitor, arg) {
  +    if (send != null) send.accept1(visitor, arg);
     }
   
     bool get isConst {
  
positive.code:     formals.accept(visitor);
    }
  
    Token getBeginToken() => typedefKeyword;
  
    Token getEndToken() => endToken;
  
negative.code: 
    accept(Visitor visitor) => visitor.visitIf(this);
  
    accept1(Visitor1 visitor, arg) => visitor.visitIf(this, arg);
  
    visitChildren(Visitor visitor) {
      if (condition != null) condition.accept(visitor);
      if (thenPart != null) thenPart.accept(visitor);
      if (elsePart != null) elsePart.accept(visitor);
    }
  
    visitChildren1(Visitor1 visitor, arg) {
      if (condition != null) condition.accept1(visitor, arg);
      if (thenPart != null) thenPart.accept1(visitor, arg);
      if (elsePart != null) elsePart.accept1(visitor, arg);
    }
  
    Token getBeginToken() => ifToken;
  