Consider Heap and Maxheap classes are already defined. Implement the following Priority Queve operations: 1. Priorityqueue (int capacity) : Constructor that initializes an empty Priority Queue with the given capacity. 2. void insert(int key, int priority) : Inserts a new element with the given key and priority into the Priority Queue. The higher the priority value, the higher the element's priority. 3. int extractmax(): Removes and returns the key of the element with the highest priority from the Priority Queue. 4. void decreasekey(int key, int newpriority): Decreases the priority of the element with the given key to the new priority value. template \\) class PriorityQueue : public MaxHeap \\( < \\) pair \\( <\\mathrm{T} \\), int \\( >>\\{ \\) public: PriorityQueue(int capacity) : MaxHeap \\( < \\) pair \\( < \\) T, int \\( >> \\) (capacity) \\{\\} // Function to insert a key and its priority into the Priority Queue // Function to extract the key with the highest priority from the Priority Queue // Function to