Set<Entry<K, V>> entrySet = map.entrySet();
    if (supportsRemove) {
      assertThrows(NullPointerException.class, () -> entrySet.removeAll(null));
    } else {
      try {
        entrySet.removeAll(null);
        fail("Expected UnsupportedOperationException or NullPointerException.");
      } catch (UnsupportedOperationException | NullPointerException e) {
        // Expected.
      }
    }
    assertInvariants(map);
  }

    EqualsTester tester = new EqualsTester();
    assertThrows(NullPointerException.class, () -> tester.addEqualityGroup((Object[]) null));
  }

  public void testNullObjectInEqualityGroup() {
    EqualsTester tester = new EqualsTester();
    NullPointerException e =
        assertThrows(NullPointerException.class, () -> tester.addEqualityGroup(1, null, 3));
    assertErrorMessage(e, "at index 1");
  }

      assertThrows(NullPointerException.class, () -> builder.add((String) null));
    }

    {
      ImmutableSet.Builder<String> builder = this.<String>builder();
      assertThrows(NullPointerException.class, () -> builder.add((String[]) null));
    }

    {
      ImmutableSet.Builder<String> builder = this.<String>builder();
      assertThrows(NullPointerException.class, () -> builder.add("a", (String) null));

    ImmutableList.Builder<String> builder = ImmutableList.builder();
    assertThrows(NullPointerException.class, () -> builder.add((String) null));

    assertThrows(NullPointerException.class, () -> builder.add((String[]) null));

    assertThrows(NullPointerException.class, () -> builder.add("a", null, "b"));
  }

  public void testBuilderAddAllHandlesNullsCorrectly() {
    {

    Set<Entry<K, V>> entrySet = map.entrySet();
    if (supportsRemove) {
      assertThrows(NullPointerException.class, () -> entrySet.removeAll(null));
    } else {
      try {
        entrySet.removeAll(null);
        fail("Expected UnsupportedOperationException or NullPointerException.");
      } catch (UnsupportedOperationException | NullPointerException e) {
        // Expected.
      }
    }
    assertInvariants(map);
  }

  public void testFind_nullNotContainedAndUnsupported() {
    try {
      assertEquals(getMethodName() + "(nullNotPresent) should return -1 or throw", -1, find(null));
    } catch (NullPointerException tolerated) {
    }
  }

  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)
  public void testFind_nonNullWhenNullContained() {
    initCollectionWithNullElement();

@ElementTypesAreNonnullByDefault
final class CollectPreconditions {

  static void checkEntryNotNull(Object key, Object value) {
    if (key == null) {
      throw new NullPointerException("null key in entry: null=" + value);
    } else if (value == null) {
      throw new NullPointerException("null value in entry: " + key + "=null");
    }
  }

  @CanIgnoreReturnValue
  static int checkNonnegative(int value, String name) {
    if (value < 0) {

   *
   * @throws NullPointerException if the element is null
   */
  public static <E> ImmutableList<E> of(E e1) {
    return new SingletonImmutableList<>(e1);
  }

  /**
   * Returns an immutable list containing the given elements, in order.
   *
   * @throws NullPointerException if any element is null
   */
  public static <E> ImmutableList<E> of(E e1, E e2) {

   * fail to insert an element only by throwing an exception.
   *
   * @throws NullPointerException if the specified element is null
   */
  @CanIgnoreReturnValue
  @Override
  public boolean offer(E e) {
    if (e == null) throw new NullPointerException();
    final Monitor monitor = this.monitor;
    if (monitor.enterIf(notFull)) {
      try {
        insert(e);

    checkResult(J, ITERABLE_123, "1-2-3");

    assertThrows(NullPointerException.class, () -> J.join(ITERABLE_NULL));
    assertThrows(NullPointerException.class, () -> J.join(ITERABLE_1_NULL_2));

    assertThrows(NullPointerException.class, () -> J.join(ITERABLE_NULL.iterator()));
    assertThrows(NullPointerException.class, () -> J.join(ITERABLE_1_NULL_2.iterator()));
  }

  public void testOnCharOverride() {