try {
      builder.putAll(Collections.<String, Integer>singletonMap(null, 1));
      fail();
    } catch (NullPointerException expected) {
    }
  }

  public void testBuilderPutNullValueViaPutAll() {
    Builder<String, Integer> builder = ImmutableSortedMap.naturalOrder();
    try {
      builder.putAll(Collections.<String, Integer>singletonMap("one", null));
      fail();

  }

  public void testCopyOf_map_nulls() {
    Map<Class<? extends Number>, Number> nullKey = Collections.singletonMap(null, (Number) 1.0);
    assertThrows(NullPointerException.class, () -> ImmutableClassToInstanceMap.copyOf(nullKey));

    Map<? extends Class<? extends Number>, Number> nullValue =
        Collections.singletonMap(Number.class, null);
    assertThrows(NullPointerException.class, () -> ImmutableClassToInstanceMap.copyOf(nullValue));

  SingletonImmutableBiMap(K key, V value) {
    super(Collections.singletonMap(checkNotNull(key), checkNotNull(value)));
    this.singleKey = key;
    this.singleValue = value;
  }

  private SingletonImmutableBiMap(K key, V value, SingletonImmutableBiMap<V, K> inverse) {
    super(Collections.singletonMap(checkNotNull(key), checkNotNull(value)));
    this.singleKey = key;
    this.singleValue = value;

    try {
      keyToPut = getKeyNotInPopulatedMap();
      valueToPut = getValueNotInPopulatedMap();
    } catch (UnsupportedOperationException e) {
      return;
    }
    Map<K, V> mapToPut = Collections.singletonMap(keyToPut, valueToPut);
    if (supportsPut) {
      int initialSize = map.size();
      map.putAll(mapToPut);
      assertEquals(valueToPut, map.get(keyToPut));
      assertTrue(map.containsKey(keyToPut));

    try {
      builder.putAll(Collections.<String, Integer>singletonMap(null, 1));
      fail();
    } catch (NullPointerException expected) {
    }
  }

  public void testBuilderPutNullValueViaPutAll() {
    Builder<String, Integer> builder = new Builder<>();
    try {
      builder.putAll(Collections.<String, Integer>singletonMap("one", null));
      fail();
    } catch (NullPointerException expected) {

  }

  public void testCopyOf_map_nulls() {
    Map<Class<? extends Number>, Number> nullKey = Collections.singletonMap(null, (Number) 1.0);
    assertThrows(NullPointerException.class, () -> ImmutableClassToInstanceMap.copyOf(nullKey));

    Map<? extends Class<? extends Number>, Number> nullValue =
        Collections.singletonMap(Number.class, null);
    assertThrows(NullPointerException.class, () -> ImmutableClassToInstanceMap.copyOf(nullValue));

              @Override
              protected Map<String, String> create(Entry<String, String>[] entries) {
                return Collections.singletonMap(entries[0].getKey(), entries[0].getValue());
              }
            })
        .named("singletonMap")
        .withFeatures(
            MapFeature.ALLOWS_NULL_KEYS,
            MapFeature.ALLOWS_NULL_VALUES,
            MapFeature.ALLOWS_ANY_NULL_QUERIES,

    assertTrue(multimap().asMap().values().remove(Collections.singletonList(v0())));
    assertEquals(2, multimap().size());
    assertEquals(
        Collections.singletonMap(k0(), Lists.newArrayList(v0(), v3())), multimap().asMap());
  }

    try {
      builder.putAll(Collections.<String, Integer>singletonMap(null, 1));
      fail();
    } catch (NullPointerException expected) {
    }
  }

  public void testBuilderPutNullValueViaPutAll() {
    Builder<String, Integer> builder = new Builder<>();
    try {
      builder.putAll(Collections.<String, Integer>singletonMap("one", null));
      fail();
    } catch (NullPointerException expected) {

    assertTrue(multimap().asMap().values().remove(Collections.singleton(v0())));
    assertEquals(2, multimap().size());
    assertEquals(Collections.singletonMap(k0(), Sets.newHashSet(v0(), v3())), multimap().asMap());
  }