java sample

// this would be the Inventory class

void addItem(Item item){
    if (this.items[item]==null){
        this.items[item]=0;
    }
    this.items[item]=this.items[item]+1;

}


// this would be the PlayerInventory class

void addItem(Item item){
    super.addItem(item);
    if (item.name=="ak47"){
        this.primaryWeapon=item;
    }
}