export class Item {
   constructor(price) {
     this.price = price;
   }
   get tax() { throw "not implemented"; }
   get subtotal() { return this.price + this.tax; }
 }
 
 export class AlcoholicBeverage extends Item {
   get tax() { return this.price * 0.25; }
 }
 
 export class NormalFood extends Item {
   get tax() { return 0; }
 }
 
 export class NonFood extends Item {
   get tax() { return this.price * 0.0825; }
 }