@Test
    public void reverseInsertAndDeleteTest(){
        long start = System.currentTimeMillis();
        for (int i = 1000000; i >= 0; i--){
            heap.insert(i);
        }
        for (int i = 0; i < 1000000; i++){
            assertEquals(heap.extract_min().value, i);
        }
        long end = System.currentTimeMillis();
        System.out.println("Time spent in inserting and deleting 1000000 in reverse: " + (end-start*1.0) + "ms");
    }