}

  /**
   * Returns a supplier which caches the instance retrieved during the first call to {@code get()}
   * and returns that value on subsequent calls to {@code get()}. See: <a
   * href="http://en.wikipedia.org/wiki/Memoization">memoization</a>
   *
   * <p>The returned supplier is thread-safe. The delegate's {@code get()} method will be invoked at

  }

  /**
   * Returns a supplier which caches the instance retrieved during the first call to {@code get()}
   * and returns that value on subsequent calls to {@code get()}. See: <a
   * href="http://en.wikipedia.org/wiki/Memoization">memoization</a>
   *
   * <p>The returned supplier is thread-safe. The delegate's {@code get()} method will be invoked at

        request.addHeader("Host", "example.com");
        result = virtualHostHelper.getVirtualHostPath(page);
        assertEquals("/site1/search", result.getRoutingPath());

        // The header remains for subsequent tests due to static request handling
        // Different matching header added to same request
        request.addHeader("X-Forwarded-Host", "test.com");
        result = virtualHostHelper.getVirtualHostPath(page);

    Object value = new Object();
    Callable<Object> callable = Callables.returning(value);
    assertThat(callable.call()).isEqualTo(value);
    // Expect the same value on subsequent calls
    assertThat(callable.call()).isEqualTo(value);
  }

  @J2ktIncompatible
  @GwtIncompatible
  public void testAsAsyncCallable() throws Exception {
    String expected = "MyCallableString";

    Object value = new Object();
    Callable<Object> callable = Callables.returning(value);
    assertThat(callable.call()).isEqualTo(value);
    // Expect the same value on subsequent calls
    assertThat(callable.call()).isEqualTo(value);
  }

  @J2ktIncompatible
  @GwtIncompatible
  public void testAsAsyncCallable() throws Exception {
    String expected = "MyCallableString";

   */
  private static void createUnreachableLatchFinalizer(CountDownLatch latch) {
    FinalizableReference.register(new Object(), latch);
  }

  /**
   * A predicate that is expected to return true subsequent to finalization, that is, one
   * of the following actions taken by the garbage collector when performing a full collection in
   * response to {@link System#gc()}:
   *
   * <ul>

   */
  private static void createUnreachableLatchFinalizer(CountDownLatch latch) {
    FinalizableReference.register(new Object(), latch);
  }

  /**
   * A predicate that is expected to return true subsequent to finalization, that is, one
   * of the following actions taken by the garbage collector when performing a full collection in
   * response to {@link System#gc()}:
   *
   * <ul>

    assertThat(callCount.get()).isEqualTo(1);
    for (int i = 0; i < count; i++) {
      assertThat(result.get(i)).isInstanceOf(InvalidCacheLoadException.class);
    }

    // subsequent calls should call the loader again, not get the old exception
    assertThrows(InvalidCacheLoadException.class, () -> cache.getUnchecked("bar"));
    assertThat(callCount.get()).isEqualTo(2);
  }

  /**

   * will never throw {@link ConcurrentModificationException}, and guarantees to traverse elements
   * as they existed upon construction of the iterator, and may (but is not guaranteed to) reflect
   * any modifications subsequent to construction.
   *
   * @return an iterator over the elements in this queue
   */
  @CanIgnoreReturnValue // pushed down from class to method
  @Override
  public Iterator<E> iterator() {

   * ConcurrentModificationException}, and guarantees to traverse elements as they existed upon
   * construction of the iterator, and may (but is not guaranteed to) reflect any modifications
   * subsequent to construction.
   *
   * @return an iterator over the elements in this queue in proper sequence
   */
  @CanIgnoreReturnValue
  @Override
  public Iterator<E> iterator() {