*
 * <p>The remainder of this documentation applies to every public {@code Immutable-} type in this
 * package, whether it is a subtype of {@code ImmutableCollection} or not.
 *
 * <h4>Guarantees</h4>
 *
 * <p>Each makes the following guarantees:
 *
 * <ul>
 *   <li><b>Shallow immutability.</b> Elements can never be added, removed or replaced in this

 *
 * <p>The remainder of this documentation applies to every public {@code Immutable-} type in this
 * package, whether it is a subtype of {@code ImmutableCollection} or not.
 *
 * <h4>Guarantees</h4>
 *
 * <p>Each makes the following guarantees:
 *
 * <ul>
 *   <li><b>Shallow immutability.</b> Elements can never be added, removed or replaced in this

 *         .transform(ActivityService::isLoggedIn, threadPool)
 *         .catching(RpcException.class, e -> false, directExecutor());
 * }
 *
 * <h3>Alternatives</h3>
 *
 * <h4>Frameworks</h4>
 *
 * <p>When chaining together a graph of asynchronous operations, you will often find it easier to
 * use a framework. Frameworks automate the process, often adding features like monitoring,