template <typename K,typename V> class HashMap{
    .
    .
    .
    public:

        class Hashable;

template<typename T> class Stack;

HashMap<NewStackClass<int>,int> map;
//T=int;K=NewStackClass<int>;V=int;

template <typename B, typename C>
template <typename A> class NewStackClass : public Stack<A>, public HashMap<B,C>::Hashable{

    virtual int hashCode() const;
    bool operator==(const MyStack<A>& stack);
};