* not in {@link #nextElements}, this method throws an {@link UnknownElementException}.
     *
     * <p>This method is used when testing iterators without a known ordering. We poll the target
     * iterator's next element and pass it to the reference iterator through this method so it can
     * return the same element. This enables the assertion to pass and the reference iterator to

  public void testPoll_empty() {
    assertNull("emptyQueue.poll() should return null", getQueue().poll());
    expectUnchanged();
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ONE)
  public void testPoll_size1() {
    assertEquals("size1Queue.poll() should return first element", e0(), getQueue().poll());
    expectMissing(e0());
  }

    assertEquals(1, (int) mmHeap.peek());
    assertEquals(1, (int) mmHeap.poll());
    assertEquals(3, (int) mmHeap.peekLast());
    assertEquals(2, (int) mmHeap.peek());
    assertEquals(2, (int) mmHeap.poll());
    assertEquals(3, (int) mmHeap.peekLast());
    assertEquals(3, (int) mmHeap.peek());
    assertEquals(3, (int) mmHeap.poll());
    assertNull(mmHeap.peekLast());
    assertNull(mmHeap.peek());

    public boolean offer(T o) {
      return standardOffer(o);
    }

    @Override
    public @Nullable T peek() {
      return standardPeek();
    }

    @Override
    public @Nullable T poll() {
      return standardPoll();
    }
  }

  public static Test suite() {
    TestSuite suite = new TestSuite();

    suite.addTestSuite(ForwardingQueueTest.class);
    suite.addTest(

        clearValueReferenceQueue();
      }
    }

    void clearKeyReferenceQueue() {
      while (keyReferenceQueue.poll() != null) {}
    }

    void clearValueReferenceQueue() {
      while (valueReferenceQueue.poll() != null) {}
    }

    // recency queue, shared by expiration and eviction

    /**

  }

  private static <K, V> void assertNotificationEnqueued(
      LocalCache<K, V> map, K key, V value, int hash) {
    RemovalNotification<K, V> notification = map.removalNotificationQueue.poll();
    assertSame(key, notification.getKey());
    assertSame(value, notification.getValue());
  }

  // Segment eviction tests

  public void testDrainRecencyQueueOnWrite() {

  }

  private static <K, V> void assertNotificationEnqueued(
      LocalCache<K, V> map, K key, V value, int hash) {
    RemovalNotification<K, V> notification = map.removalNotificationQueue.poll();
    assertSame(key, notification.getKey());
    assertSame(value, notification.getValue());
  }

  // Segment eviction tests

  public void testDrainRecencyQueueOnWrite() {

    }
  }

  void checkEmpty(BlockingQueue<?> q) {
    try {
      assertTrue(q.isEmpty());
      assertEquals(0, q.size());
      assertNull(q.peek());
      assertNull(q.poll());
      assertNull(q.poll(0, MILLISECONDS));
      assertEquals("[]", q.toString());
      assertTrue(Arrays.equals(q.toArray(), new Object[0]));
      assertFalse(q.iterator().hasNext());
      try {
        q.element();

            .removalListener(listener)
            .ticker(ticker)
            .build();
    cache.put(1, 1);
    ticker.advance(10, TimeUnit.MINUTES);
    cache.invalidateAll();

    assertThat(listener.poll().getCause()).isEqualTo(RemovalCause.EXPIRED);
  }

  private void runRemovalScheduler(
      LoadingCache<String, Integer> cache,
      CountingRemovalListener<String, Integer> removalListener,

     * not in {@link #nextElements}, this method throws an {@link UnknownElementException}.
     *
     * <p>This method is used when testing iterators without a known ordering. We poll the target
     * iterator's next element and pass it to the reference iterator through this method so it can
     * return the same element. This enables the assertion to pass and the reference iterator to