* </ul>
 *
 * <h4>"Interfaces", not implementations</h4>
 *
 * <p>These are classes instead of interfaces to prevent external subtyping, but should be thought
 * of as interfaces in every important sense. Each public class such as {@link ImmutableSet} is a
 * <i>type</i> offering meaningful behavioral guarantees. This is substantially different from the

 * </ul>
 *
 * <h4>"Interfaces", not implementations</h4>
 *
 * <p>These are classes instead of interfaces to prevent external subtyping, but should be thought
 * of as interfaces in every important sense. Each public class such as {@link ImmutableSet} is a
 * <i>type</i> offering meaningful behavioral guarantees. This is substantially different from the