}

  public void testPowerSetIteration_manual() {
    ImmutableSet<Integer> elements = ImmutableSet.of(1, 2, 3);
    Set<Set<Integer>> powerSet = powerSet(elements);
    // The API doesn't promise this iteration order, but it's convenient here.
    Iterator<Set<Integer>> i = powerSet.iterator();
    assertEquals(ImmutableSet.of(), i.next());
    assertEquals(ImmutableSet.of(1), i.next());

       * template to be null (though we do handle that case gracefully at runtime). I've left this
       * one as it is because one of our users has defined a wrapper API around Preconditions,
       * declaring a checkState method that accepts a possibly null template. So we'd need to update
       * that user first.
       */
      @CheckForNull String errorMessageTemplate,

 *
 * <h2>Prefer <a href="https://github.com/ben-manes/caffeine/wiki">Caffeine</a> over Guava's caching
 * API</h2>
 *
 * <p>The successor to Guava's caching API is <a
 * href="https://github.com/ben-manes/caffeine/wiki">Caffeine</a>. Its API is designed to make it a
 * nearly drop-in replacement. It requires Java 8+, and is not available for Android or GWT/J2CL,

 * assigned characters, including important CJK characters and emoji.
 *
 * <p>Supplementary characters are <a
 * href="https://docs.oracle.com/javase/8/docs/api/java/lang/Character.html#supplementary">encoded
 * into a {@code String} using surrogate pairs</a>, and a {@code CharMatcher} treats these just as

 * assigned characters, including important CJK characters and emoji.
 *
 * <p>Supplementary characters are <a
 * href="https://docs.oracle.com/javase/8/docs/api/java/lang/Character.html#supplementary">encoded
 * into a {@code String} using surrogate pairs</a>, and a {@code CharMatcher} treats these just as

    public Container(T data) {}
  }

  public <T extends Container<String>> void testConstructor_parameterTypes()
      throws NoSuchMethodException {
    @SuppressWarnings("rawtypes") // Reflection API skew
    Constructor<Container> constructor = Container.class.getConstructor(Object.class);
    Invokable<T, ?> invokable = new TypeToken<T>(getClass()) {}.constructor(constructor);

     *
     * On the other hand, the current signature is consistent with the similar allAsList method. And
     * eventually this method may go away entirely in favor of an API like
     * whenAllComplete().collectSuccesses(). That API would have a signature more like the current
     * one.
     */
    return new ListFuture<V>(ImmutableList.copyOf(futures), false);
  }

  /**

       * template to be null (though we do handle that case gracefully at runtime). I've left this
       * one as it is because one of our users has defined a wrapper API around Preconditions,
       * declaring a checkState method that accepts a possibly null template. So we'd need to update
       * that user first.
       */
      @CheckForNull String errorMessageTemplate,

    public Container(T data) {}
  }

  public <T extends Container<String>> void testConstructor_parameterTypes()
      throws NoSuchMethodException {
    @SuppressWarnings("rawtypes") // Reflection API skew
    Constructor<Container> constructor = Container.class.getConstructor(Object.class);
    Invokable<T, ?> invokable = new TypeToken<T>(getClass()) {}.constructor(constructor);