template <typename Key, typename Element> class AVLItem : public Item<Key,Element> { // an AVL item private: int hgt; // node height public: AVLItem(const Key& k = Key(), const Element& e = Element(), int h = 0) : Item<Key, Element>(k, e), hgt(h) { } int height() const { return hgt; } // get height void setHeight(int h) { hgt = h; } // set height };