*/
  public static <K, V> ImmutableMultimap<K, V> copyOf(Multimap<? extends K, ? extends V> multimap) {
    if (multimap instanceof ImmutableMultimap) {
      @SuppressWarnings("unchecked") // safe since multimap is not writable
      ImmutableMultimap<K, V> kvMultimap = (ImmutableMultimap<K, V>) multimap;
      if (!kvMultimap.isPartialView()) {
        return kvMultimap;
      }

   */
  public static <K, V> ImmutableMultimap<K, V> copyOf(Multimap<? extends K, ? extends V> multimap) {
    if (multimap instanceof ImmutableMultimap) {
      @SuppressWarnings("unchecked") // safe since multimap is not writable
      ImmutableMultimap<K, V> kvMultimap = (ImmutableMultimap<K, V>) multimap;
      if (!kvMultimap.isPartialView()) {
        return kvMultimap;
      }

    assertEquals("", j.join(ImmutableMultimap.of().entries()));
    assertEquals("", j.join(ImmutableMultimap.of().entries().iterator()));
    assertEquals(":", j.join(ImmutableMultimap.of("", "").entries()));
    assertEquals(":", j.join(ImmutableMultimap.of("", "").entries().iterator()));
    assertEquals("1:a;1:b", j.join(ImmutableMultimap.of("1", "a", "1", "b").entries()));

          .put(ImmutableSortedMap.class, ImmutableSortedMap.of())
          .put(NavigableMap.class, Maps.unmodifiableNavigableMap(Maps.newTreeMap()))
          .put(Multimap.class, ImmutableMultimap.of())
          .put(ImmutableMultimap.class, ImmutableMultimap.of())
          .put(ListMultimap.class, ImmutableListMultimap.of())
          .put(ImmutableListMultimap.class, ImmutableListMultimap.of())

  }

  public void testInvertFrom() {
    ImmutableMultimap<Integer, String> empty = ImmutableMultimap.of();

    // typical usage example - sad that ArrayListMultimap.create() won't work
    Multimap<String, Integer> multimap =
        Multimaps.invertFrom(empty, ArrayListMultimap.<String, Integer>create());
    assertTrue(multimap.isEmpty());

    ImmutableMultimap<Integer, String> single =

    assertEquals("", j.join(ImmutableMultimap.of().entries()));
    assertEquals("", j.join(ImmutableMultimap.of().entries().iterator()));
    assertEquals(":", j.join(ImmutableMultimap.of("", "").entries()));
    assertEquals(":", j.join(ImmutableMultimap.of("", "").entries().iterator()));
    assertEquals("1:a;1:b", j.join(ImmutableMultimap.of("1", "a", "1", "b").entries()));

                return wrap((Multimap<?, ?>) delegate);
              }
            });
  }

  public void testEquals() {
    Multimap<Integer, String> map1 = ImmutableMultimap.of(1, "one");
    Multimap<Integer, String> map2 = ImmutableMultimap.of(2, "two");
    new EqualsTester()
        .addEqualityGroup(map1, wrap(map1), wrap(map1))
        .addEqualityGroup(map2, wrap(map2))
        .testEquals();
  }

      derivedFeatures.remove(CollectionFeature.SERIALIZABLE);
    }
    return derivedFeatures;
  }

  private static final ImmutableMultimap<Feature<?>, Feature<?>> GET_FEATURE_MAP =
      ImmutableMultimap.<Feature<?>, Feature<?>>builder()
          .put(
              MapFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION,
              CollectionFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION)

          .put(ImmutableSortedMap.class, ImmutableSortedMap.of())
          .put(NavigableMap.class, Maps.unmodifiableNavigableMap(Maps.newTreeMap()))
          .put(Multimap.class, ImmutableMultimap.of())
          .put(ImmutableMultimap.class, ImmutableMultimap.of())
          .put(ListMultimap.class, ImmutableListMultimap.of())
          .put(ImmutableListMultimap.class, ImmutableListMultimap.of())

    assertTrue(ArbitraryInstances.get(SortedMultiset.class).isEmpty());
    assertEquals(ImmutableMultimap.of(), ArbitraryInstances.get(Multimap.class));
    assertEquals(ImmutableMultimap.of(), ArbitraryInstances.get(ImmutableMultimap.class));
    assertTrue(ArbitraryInstances.get(SortedSetMultimap.class).isEmpty());
    assertEquals(ImmutableTable.of(), ArbitraryInstances.get(Table.class));