* represent the same element and count. That is, two entries {@code a} and {@code b} are equal
     * if:
     *
     * <pre>{@code
     * Objects.equal(a.getElement(), b.getElement())
     *     && a.getCount() == b.getCount()
     * }</pre>
     */
    @Override
    // TODO(kevinb): check this wrt TreeMultiset?
    boolean equals(@CheckForNull Object o);

    /**
     * {@inheritDoc}

   * final} multimaps ("constant multimaps"). Example:
   *
   * <pre>{@code
   * static final Multimap<String, Integer> STRING_TO_INTEGER_MULTIMAP =
   *     new ImmutableSetMultimap.Builder<String, Integer>()
   *         .put("one", 1)
   *         .putAll("several", 1, 2, 3)
   *         .putAll("many", 1, 2, 3, 4, 5)
   *         .build();
   * }</pre>
   *

 *
 * <p>For example, to test {@link java.util.Collections#unmodifiableList(java.util.List)
 * Collections.unmodifiableList}'s iterator:
 *
 * <pre>{@code
 * List<String> expectedElements =
 *     Arrays.asList("a", "b", "c", "d", "e");
 * List<String> actualElements =
 *     Collections.unmodifiableList(
 *         Arrays.asList("a", "b", "c", "d", "e"));

 * factory classes like:
 *
 * <pre>
 * interface Book {...}
 * public class Books {
 *   public static Book hardcover(String title) {...}
 *   public static Book paperback(String title) {...}
 * }
 * </pre>
 *
 * <p>And all the created {@code Book} instances can be tested with:
 *
 * <pre>
 * new ClassSanityTester()
 *     .forAllPublicStaticMethods(Books.class)

   * empty, passed directly to this method, and no reference to the map is retained, as illustrated
   * in the following code fragment:
   *
   * <pre>{@code
   * Set<Object> identityHashSet = Sets.newSetFromMap(
   *     new IdentityHashMap<Object, Boolean>());
   * }</pre>
   *
   * <p>The returned set is serializable if the backing map is.
   *
   * @param map the backing map
   * @return the set backed by the map

 * iteration order guarantees.
 *
 * <p>Example usage:
 *
 * <pre>{@code
 * MutableGraph<Integer> graph =
 *     GraphBuilder.directed().nodeOrder(ElementOrder.<Integer>natural()).build();
 * }</pre>
 *
 * @author Joshua O'Madadhain
 * @since 20.0
 */
@Beta
@Immutable
@ElementTypesAreNonnullByDefault
public final class ElementOrder<T> {

   * graphs. Example:
   *
   * <pre>{@code
   * static final ImmutableGraph<Country> COUNTRY_ADJACENCY_GRAPH =
   *     GraphBuilder.undirected()
   *         .<Country>immutable()
   *         .putEdge(FRANCE, GERMANY)
   *         .putEdge(FRANCE, BELGIUM)
   *         .putEdge(GERMANY, BELGIUM)
   *         .addNode(ICELAND)
   *         .build();
   * }</pre>
   *

 * create an instance of one of the built-in implementations of {@code ValueGraph}, use the {@link
 * ValueGraphBuilder} class:
 *
 * <pre>{@code
 * MutableValueGraph<Integer, Double> graph = ValueGraphBuilder.directed().build();
 * }</pre>
 *
 * <p>{@link ValueGraphBuilder#build()} returns an instance of {@link MutableValueGraph}, which is a

 * the same parameters forwarded and return value forwarded back or exception propagated as is.
 *
 * <p>For example:
 *
 * <pre>{@code
 * new ForwardingWrapperTester().testForwarding(Foo.class, new Function<Foo, Foo>() {
 *   public Foo apply(Foo foo) {
 *     return new ForwardingFoo(foo);
 *   }
 * });
 * }</pre>
 *
 * @author Ben Yu
 * @since 14.0
 */
@GwtIncompatible
@J2ktIncompatible
@ElementTypesAreNonnullByDefault

 * returns a <b>(live) unmodifiable view</b>; see <a
 * href="https://github.com/google/guava/wiki/GraphsExplained#accessor-behavior">the external
 * documentation</a> for details.
 *
 * <p>Examples of use:
 *
 * <pre>{@code
 * // Building a mutable value graph
 * MutableValueGraph<String, Double> graph =
 *     ValueGraphBuilder.undirected().allowsSelfLoops(true).build();
 * graph.putEdgeValue("San Francisco", "San Francisco", 0.0);