@Test public void shouldBehaveExactlyLikeAnotherPriorityQueue() { for (int i = 0; i < 10; i++) { final Random random = getRandom(-1); final java.util.PriorityQueue<Integer> mutablePriorityQueue = new java.util.PriorityQueue<>(); javaslang.collection.PriorityQueue<Integer> functionalPriorityQueue = javaslang.collection.PriorityQueue.empty(); final int size = 100_000; for (int j = 0; j < size; j++) { /* Insert */ if (random.nextInt() % 3 == 0) { assertMinimumsAreEqual(mutablePriorityQueue, functionalPriorityQueue); final int value = random.nextInt(size) - (size / 2); mutablePriorityQueue.add(value); functionalPriorityQueue = functionalPriorityQueue.enqueue(value); } assertMinimumsAreEqual(mutablePriorityQueue, functionalPriorityQueue); /* Delete */ if (random.nextInt() % 5 == 0) { if (!mutablePriorityQueue.isEmpty()) { mutablePriorityQueue.poll(); } if (!functionalPriorityQueue.isEmpty()) { functionalPriorityQueue = functionalPriorityQueue.tail(); } assertMinimumsAreEqual(mutablePriorityQueue, functionalPriorityQueue); } } final Collection<Integer> oldValues = mutablePriorityQueue.stream().sorted().collect(toList()); final Collection<Integer> newValues = functionalPriorityQueue.toJavaList(); assertThat(oldValues).isEqualTo(newValues); } }