if (isSatisfied(guard)) {
        guard.condition.signal();
        break;
      }
    }
  }

  /**
   * Exactly like signalNextWaiter, but caller guarantees that guardToSkip need not be considered,
   * because caller has previously checked that guardToSkip.isSatisfied() returned false. An
   * optimization for the case that guardToSkip.isSatisfied() may be expensive.
   *

 * expressions it can be specified even more easily:
 *
 * <pre>{@code
 * CacheLoader<Key, Graph> loader = CacheLoader.from(key -> createExpensiveGraph(key));
 * }</pre>
 *
 * @author Charles Fry
 * @since 10.0
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public abstract class CacheLoader<K, V> {
  /** Constructor for use by subclasses. */
  protected CacheLoader() {}

  /**

   * href="ImmutableMultimap.html#iteration">grouped by key</a>.
   *
   * <p>Example:
   *
   * <pre>{@code
   * static final Multimap<Character, String> FIRST_LETTER_MULTIMAP =
   *     Stream.of("banana", "apple", "carrot", "asparagus", "cherry")
   *         .collect(toImmutableSetMultimap(str -> str.charAt(0), str -> str.substring(1)));
   *
   * // is equivalent to
   *
   * static final Multimap<Character, String> FIRST_LETTER_MULTIMAP =

 * by multiple concurrent threads.
 *
 * @param <K> the type of the cache's keys, which are not permitted to be null
 * @param <V> the type of the cache's values, which are not permitted to be null
 * @author Charles Fry
 * @since 10.0
 */
@DoNotMock("Use CacheBuilder.newBuilder().build()")
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface Cache<K, V> {

  /**

    @SuppressWarnings("unused") // Called by reflection
    private void privateMethod() {}

    @SuppressWarnings("unused") // Called by reflection
    void packagePrivateMethod() {}

    @SuppressWarnings("unused") // Called by reflection
    protected void protectedMethod() {}

    @SuppressWarnings("unused") // Called by reflection
    public void publicMethod() {}
  }

   * UncheckedTimeoutException} to the caller.
   *
   * <p>It is important to note that the primary purpose of the proxy object is to return control to
   * the caller when the timeout elapses; aborting the target method call is of secondary concern.
   * The particular nature and strength of the guarantees made by the proxy is

        new FutureCallback<String>() {
          private boolean called = false;

          @Override
          public void onSuccess(String result) {
            fail("Was not expecting onSuccess() to be called.");
          }

          @Override
          public synchronized void onFailure(Throwable t) {
            assertFalse(called);
            assertThat(t).isInstanceOf(CancellationException.class);

    assertEquals(1, listenerLatch.getCount());
    assertFalse(task.isDone());
    assertFalse(task.isCancelled());

    // Finish the task by unblocking the task latch.  Then wait for the
    // listener to be called by blocking on the listener latch.
    taskLatch.countDown();
    assertEquals(25, task.get().intValue());
    assertTrue(listenerLatch.await(5, TimeUnit.SECONDS));
    assertTrue(task.isDone());

    final boolean[] called = new boolean[1];
    f.addCallback(
        new FutureCallback<String>() {
          @Override
          public void onSuccess(String result) {
            called[0] = true;
          }

          @Override
          public void onFailure(Throwable t) {}
        },
        directExecutor());
    assertThat(called[0]).isTrue();
  }

   * be thread-safe.
   *
   * @since 13.0
   */
  public interface Policy {

    /**
     * Called when a potential deadlock is encountered. Implementations can throw the given {@code
     * exception} and/or execute other desired logic.
     *
     * <p>Note that the method will be called even upon an invocation of {@code tryLock()}. Although