class Game {
    
    void createItem(String name, Integer value, String description = '') { ... }    
   
    void increaseValueOfItem(String name, Integer amount) { ... }
    
    void decreaseValueOfItem(String name, Integer amount) { ... }
    
    Integer getValueOfItem(String name) { ... }
    
    Integer getTotalValueOfItems() { ... }
    
    Item findItem(name) { ... }
 
    def name             // name of game
    def items = [ : ]    // items in the game
}