ImmutableSortedMap<String, Integer> map =
        ImmutableSortedMap.<String, Integer>naturalOrder()
            .putAll(Collections.<String, Integer>emptyMap())
            .build();
    assertEquals(Collections.<String, Integer>emptyMap(), map);
  }

  public void testBuilderPutAll() {
    Map<String, Integer> toPut = new LinkedHashMap<>();
    toPut.put("one", 1);
    toPut.put("two", 2);

  }

  @MapFeature.Require(SUPPORTS_PUT)
  public void testPutAll_supportedNothing() {
    getMap().putAll(emptyMap());
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  public void testPutAll_unsupportedNothing() {
    try {
      getMap().putAll(emptyMap());
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

  // Creation tests

  public void testEmptyBuilder() {
    ImmutableBiMap<String, Integer> map = new Builder<String, Integer>().build();
    assertEquals(Collections.<String, Integer>emptyMap(), map);
    assertEquals(Collections.<Integer, String>emptyMap(), map.inverse());
    assertSame(ImmutableBiMap.of(), map);
  }

  public void testSingletonBuilder() {

  // Creation tests

  public void testEmptyBuilder() {
    ImmutableBiMap<String, Integer> map = new Builder<String, Integer>().build();
    assertEquals(Collections.<String, Integer>emptyMap(), map);
    assertEquals(Collections.<Integer, String>emptyMap(), map.inverse());
    assertSame(ImmutableBiMap.of(), map);
  }

  public void testSingletonBuilder() {

    ImmutableSortedMap<String, Integer> map =
        ImmutableSortedMap.<String, Integer>naturalOrder()
            .putAll(Collections.<String, Integer>emptyMap())
            .build();
    assertEquals(Collections.<String, Integer>emptyMap(), map);
  }

  public void testBuilderPutAll() {
    Map<String, Integer> toPut = new LinkedHashMap<>();
    toPut.put("one", 1);
    toPut.put("two", 2);

    assertSame(
        ImmutableClassToInstanceMap.of(),
        SerializableTester.reserialize(ImmutableClassToInstanceMap.of()));
  }

  public void testCopyOf_map_empty() {
    Map<Class<?>, Object> in = Collections.emptyMap();
    ClassToInstanceMap<Object> map = ImmutableClassToInstanceMap.copyOf(in);
    assertTrue(map.isEmpty());
    assertSame(map, ImmutableClassToInstanceMap.of());
    assertSame(map, ImmutableClassToInstanceMap.copyOf(map));

            .add(SHORT_NAME, Collections.singletonMap("k1", "v1"))
            .add(LONG_NAME, Collections.singletonMap("k2", "v2"))
            .addValue(Collections.singletonMap("k3", "v3"))
            .addValue(Collections.emptyMap())
            .addValue(null)
            .add(SHORT_NAME, Optional.of("1"))
            .add(LONG_NAME, Optional.of("1"))
            .add(SHORT_NAME, Optional.absent())
            .add(LONG_NAME, Optional.absent())

            new TestStringMapGenerator() {
              @Override
              protected Map<String, String> create(Entry<String, String>[] entries) {
                return Collections.emptyMap();
              }
            })
        .named("emptyMap")
        .withFeatures(CollectionFeature.SERIALIZABLE, CollectionSize.ZERO)
        .suppressing(suppressForEmptyMap())
        .createTestSuite();
  }

  }

  @MapFeature.Require(SUPPORTS_PUT)
  public void testPutAll_supportedNothing() {
    getMap().putAll(emptyMap());
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  public void testPutAll_unsupportedNothing() {
    try {
      getMap().putAll(emptyMap());
    } catch (UnsupportedOperationException tolerated) {
    }
    expectUnchanged();
  }

    assertEquals(Collections.emptyMap(), map);
  }

  public void testConcurrentMap() {
    ConcurrentMap<Integer, Integer> map = Maps.newConcurrentMap();
    assertEquals(Collections.emptyMap(), map);
  }

  public void testTreeMap() {
    TreeMap<Integer, Integer> map = Maps.newTreeMap();
    assertEquals(Collections.emptyMap(), map);
    assertNull(map.comparator());
  }