assertFalse(future.isCancelled());
  }

  public void testSetValue_simpleThreaded() throws Exception {
    SettableFuture<Integer> future = SettableFuture.create();
    assertTrue(future.set(42));
    // Later attempts to set the future should return false.
    assertFalse(future.set(23));
    assertFalse(future.setException(new Exception("bar")));
    assertFalse(future.setFuture(SettableFuture.<Integer>create()));

    assertFalse(future.isCancelled());
  }

  public void testSetValue_simpleThreaded() throws Exception {
    SettableFuture<Integer> future = SettableFuture.create();
    assertTrue(future.set(42));
    // Later attempts to set the future should return false.
    assertFalse(future.set(23));
    assertFalse(future.setException(new Exception("bar")));
    assertFalse(future.setFuture(SettableFuture.<Integer>create()));

  }

  public void testEntrySetToArrayMutationThrows() {
    map.putInstance(String.class, "test");
    @SuppressWarnings("unchecked") // Should get a CCE later if cast is wrong
    Entry<?, Object> entry = (Entry<?, Object>) map.entrySet().toArray()[0];
    assertEquals(TypeToken.of(String.class), entry.getKey());
    assertEquals("test", entry.getValue());

   * and {@code intern(a) == intern(b)} if and only if {@code a.equals(b)}. Note that {@code
   * intern(a)} is permitted to return one instance now and a different instance later if the
   * original interned instance was garbage-collected.
   *
   * <p><b>Warning:</b> do not use with mutable objects.
   *
   * @throws NullPointerException if {@code sample} is null
   */
  E intern(E sample);

  /** The first exception encountered if any threadAssertXXX method fails. */
  private final AtomicReference<Throwable> threadFailure = new AtomicReference<>(null);

  /**
   * Records an exception so that it can be rethrown later in the test harness thread, triggering a
   * test case failure. Only the first failure is recorded; subsequent calls to this method from
   * within the same test have no effect.
   */

     * best we can do (since logging may overflow the stack) is to let the error propagate. Because
     * it is an Error, it won't be caught and logged by AbstractFuture.executeListener. Instead, it
     * can propagate through many layers of AbstractTransformFuture up to the root call to set().
     *
     * https://github.com/google/guava/issues/2254
     *
     * Other kinds of Errors are possible:
     *

      return false;
    }

    /**
     * Returns a string in the format specified by {@link MoreObjects#toStringHelper(Object)}.
     *
     * <p>After calling this method, you can keep adding more properties to later call toString()
     * again and get a more complete representation of the same object; but properties cannot be
     * removed, so this only allows limited reuse of the helper instance. The helper allows

    }
  }

  /**
   * On a concurrent computation that returns null, all threads should get an
   * InvalidCacheLoadException, with the loader only called once. The result should not be cached (a
   * later request should call the loader again).
   */
  private static void testConcurrentLoadingNull(CacheBuilder<Object, Object> builder)
      throws InterruptedException {

    int count = 10;

    @Nullable Object[] alternatingKeysAndValues;
    int size;
    boolean entriesUsed;
    /**
     * If non-null, a duplicate key we found in a previous buildKeepingLast() or buildOrThrow()
     * call. A later buildOrThrow() can simply report this duplicate immediately.
     */
    @Nullable DuplicateKey duplicateKey;

    /**
     * Creates a new builder. The returned builder is equivalent to the builder generated by {@link

     * e.g. hash codes adversarially designed to go into ascending table locations, which keeps
     * construction O(n) (as desired) but then can have O(n) queries later.
     *
     * <p>If this returns false, then no query can take more than O(log n).
     *
     * <p>Note that for a RegularImmutableSet with elements with truly random hash codes, contains