/** Cleanup collected entries when the lock is available. */
    void tryDrainReferenceQueues() {
      if (tryLock()) {
        try {
          maybeDrainReferenceQueues();
        } finally {
          unlock();
        }
      }
    }

    @GuardedBy("this")
    void drainKeyReferenceQueue(ReferenceQueue<K> keyReferenceQueue) {
      Reference<? extends K> ref;
      int i = 0;

    mod.add(3);

    NavigableSet<Integer> unmod = unmodifiableNavigableSet(mod);

    /* Unmodifiable is a view. */
    mod.add(4);
    assertTrue(unmod.contains(4));
    assertTrue(unmod.descendingSet().contains(4));

    ensureNotDirectlyModifiable(unmod);
    ensureNotDirectlyModifiable(unmod.descendingSet());
    ensureNotDirectlyModifiable(unmod.headSet(2));

    CacheLoader<Object, Object> loader =
        new CacheLoader<Object, Object>() {
          @Override
          public Object load(Object key) {
            return one;
          }

          @Override
          public ListenableFuture<Object> reload(Object key, Object oldValue) {
            return Futures.immediateFuture(two);
          }
        };

    Iterator<String> mod = Lists.newArrayList("a", "b", "c").iterator();
    UnmodifiableIterator<String> unmod = Iterators.unmodifiableIterator(mod);
    assertNotSame(mod, unmod);
    assertSame(unmod, Iterators.unmodifiableIterator(unmod));
    assertSame(unmod, Iterators.unmodifiableIterator((Iterator<String>) unmod));
  }

  @SuppressWarnings("deprecation")
  public void testPeekingIteratorShortCircuit() {

    CacheLoader<Object, Object> loader =
        new CacheLoader<Object, Object>() {
          @Override
          public Object load(Object key) {
            return one;
          }

          @Override
          public ListenableFuture<Object> reload(Object key, Object oldValue) {
            return Futures.immediateFuture(two);
          }
        };

    public SearchApiManager() {
        setPathPrefix("/api/v1");
    }

    @PostConstruct
    public void register() {
        if (logger.isInfoEnabled()) {
            logger.info("Load {}", this.getClass().getSimpleName());
        }
        ComponentUtil.getWebApiManagerFactory().add(this);
    }

    @Override
    protected FormatType detectFormatType(final HttpServletRequest request) {

   * of refreshes are specified in {@link LoadingCache#refresh}, and are performed by calling {@link
   * CacheLoader#reload}.
   *
   * <p>As the default implementation of {@link CacheLoader#reload} is synchronous, it is
   * recommended that users of this method override {@link CacheLoader#reload} with an asynchronous
   * implementation; otherwise refreshes will be performed during unrelated cache read and write
   * operations.