* instance, since {@code PermittedExceptions} is thrown only when a method call is invalid.
   *
   * <p>This class is accessible but not supported in GWT as it references {@link
   * PermittedMetaException}.
   */
  protected final class MultiExceptionListIterator implements ListIterator<E> {
    // TODO: track seen elements when order isn't guaranteed
    // TODO: verify contents afterward

          Reflection.newProxy(Map.class, new CheckSetUpInvocationHandler(map, setUpRan));
      return proxy;
    }
  }

  /**
   * Intercepts calls to a {@code Map} to check that {@code setUpRan} is true when they happen. Then
   * forwards the calls to the underlying {@code Map}.
   */
  private static class CheckSetUpInvocationHandler implements InvocationHandler, Serializable {
    private final Map<String, String> map;

 *       when using Executors.
 * </ol>
 *
 * <p><b>Other notes</b>
 *
 * <ul>
 *   <li>Usually, there is one testcase method per JSR166 method covering "normal" operation, and
 *       then as many exception-testing methods as there are exceptions the method can throw.
 *       Sometimes there are multiple tests per JSR166 method when the different "normal" behaviors

          Reflection.newProxy(Map.class, new CheckSetUpInvocationHandler(map, setUpRan));
      return proxy;
    }
  }

  /**
   * Intercepts calls to a {@code Map} to check that {@code setUpRan} is true when they happen. Then
   * forwards the calls to the underlying {@code Map}.
   */
  private static class CheckSetUpInvocationHandler implements InvocationHandler, Serializable {
    private final Map<String, String> map;

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A helper for concurrency testing. One or more {@code TestThread} instances are instantiated in a
 * test with reference to the same "lock-like object", and then their interactions with that object
 * are choreographed via the various methods on this class.
 *
 * <p>A "lock-like object" is really any object that may be used for concurrency control. If the

    forward.invalidateAll();
    verify(mock).invalidateAll();
  }

  public void testSize() {
    when(mock.size()).thenReturn(0L);
    assertEquals(0, forward.size());
  }

  public void testStats() {
    when(mock.stats()).thenReturn(null);
    assertNull(forward.stats());
  }

  public void testAsMap() {
    when(mock.asMap()).thenReturn(null);
    assertNull(forward.asMap());
  }

  public void testCleanUp() {

 *
 * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
 * views are modifiable.
 *
 * <p>This class is not threadsafe when any concurrent operations update the multimap. Concurrent
 * read operations will work correctly. To allow concurrent update operations, wrap your multimap
 * with a call to {@link Multimaps#synchronizedListMultimap}.
 *

   * elements. The generated map is sorted by the specified comparator.
   *
   * <p>If the mapped keys contain duplicates (according to the specified comparator), an {@code
   * IllegalArgumentException} is thrown when the collection operation is performed. (This differs
   * from the {@code Collector} returned by {@link Collectors#toMap(Function, Function)}, which
   * throws an {@code IllegalStateException}.)
   *

   *
   * <pre>{@code
   * // Falling back to a zero counter in case an exception happens when processing the RPC to fetch
   * // counters.
   * ListenableFuture<Integer> faultTolerantFuture =
   *     fetchCounters().catching(FetchException.class, x -> 0, directExecutor());
   * }</pre>
   *
   * <p>When selecting an executor, note that {@code directExecutor} is dangerous in some cases. See

  }

  /**
   * Returns a hash function implementing the MD5 hash algorithm (128 hash bits).
   *
   * @deprecated If you must interoperate with a system that requires MD5, then use this method,
   *     despite its deprecation. But if you can choose your hash function, avoid MD5, which is
   *     neither fast nor secure. As of January 2017, we suggest:
   *     <ul>
   *       <li>For security: