PriorityQueue<Integer> priorityQueue = new PriorityQueue<>();
PriorityQueue<Integer> priorityQueue = new PriorityQueue<>(Collections.reverseOrder());
PriorityQueue<String> priorityQueue = new PriorityQueue<>();
PriorityQueue<String> priorityQueue = new PriorityQueue<>(Collections.reverseOrder());
priorityQueue.add(7);
priorityQueue.poll();
priorityQueue.remove();
priorityQueue.clear();
priorityQueue.peek();