Food have?
    display()Toy have?
    display() and calculateTax()
Here is a class definition for Goods:
class Goods
{
  String description;
  double price;
  Goods( String des, double pr )
  {
    description = des;
    price       = pr;
  }
  void display()
  {
    System.out.println( "item: " + description +  " price: " + price );
  }
}
Here is a skeleton of the class Food,
a child of Goods.
It adds the variable calories.