Implement a priority queue (priorities will be integers) using a doubly linked list. Assume that the smaller the integer the higher priority. The main operations of the priority queue are: add (n): inserts priority n. max: returns (but does not delete) the highest priority. removeMax(): removes a highest priority. Write a tester class and name it Main. You are expected to structure the code as indicated in the UML class diagram:

Java

PriorityQueue Main Node first Node last +PriorityQueue(0 +boolean isEmpty +void add (int x) +int max +void removeMax() +static void main(String args) +Main() Node -int info Node next Node prev +Node0 +void setinfo(int i) +void setNext(Node p) +setPrev(Node p) +int getlnfo) +Node getNext +Node getPrev)