@CollectionSize.Require(absent = ZERO)
  public void testAdd_supportedNullPresent() {
    E[] array = createArrayWithNullElement();
    collection = getSubjectGenerator().create(array);
    assertFalse("add(nullPresent) should return false", getSet().add(null));
    expectContents(array);
  }

  /**
   * Returns the {@link Method} instance for {@link #testAdd_supportedNullPresent()} so that tests

    @SuppressWarnings("unchecked")
    Entry<String, String>[] array = (Entry<String, String>[]) new Entry<?, ?>[entries.length];
    int i = 0;
    for (Object o : entries) {
      @SuppressWarnings("unchecked")
      Entry<String, String> e = (Entry<String, String>) o;
      array[i++] = e;
    }
    return create(array);
  }

  protected abstract BiMap<String, String> create(Entry<String, String>[] entries);

    @SuppressWarnings("unchecked")
    Entry<String, String>[] array = (Entry<String, String>[]) new Entry<?, ?>[entries.length];
    int i = 0;
    for (Object o : entries) {
      @SuppressWarnings("unchecked")
      Entry<String, String> e = (Entry<String, String>) o;
      array[i++] = e;
    }
    return create(array);
  }

    @SuppressWarnings("unchecked") // Trying to test generic array
    ImmutableList<Integer>[] array =
        (ImmutableList<Integer>[]) new ImmutableList<?>[] {ImmutableList.of(1)};
    TypeToken<ImmutableList<Integer>[]> type = new TypeToken<ImmutableList<Integer>[]>() {};
    ImmutableTypeToInstanceMap<Iterable<?>[]> map =
        ImmutableTypeToInstanceMap.<Iterable<?>[]>builder().put(type, array).build();
    assertEquals(1, map.size());

  }

  public void testCreation_emptyArray() {
    String[] array = new String[0];
    Multiset<String> multiset = ImmutableMultiset.copyOf(array);
    assertTrue(multiset.isEmpty());
  }

  public void testCreation_arrayOfOneElement() {
    String[] array = new String[] {"a"};
    Multiset<String> multiset = ImmutableMultiset.copyOf(array);
    assertEquals(HashMultiset.create(asList("a")), multiset);
  }

    ImmutableList<Integer>[] array =
        (ImmutableList<Integer>[]) new ImmutableList<?>[] {ImmutableList.of(1)};
    TypeToken<ImmutableList<Integer>[]> type = new TypeToken<ImmutableList<Integer>[]>() {};
    map.putInstance(type, array);
    assertEquals(1, map.size());
    assertThat(map.getInstance(type)).asList().containsExactly(array[0]);
  }

     * to equals(), and we will deduplicate those properly, albeit at some cost in allocations.
     */
    int expectedSize =
        elements instanceof Set ? array.length : estimatedSizeForUnknownDuplication(array.length);
    return fromArrayWithExpectedSize(array, expectedSize);
  }

  /**
   * Returns an immutable set containing each of {@code elements}, minus duplicates, in the order

   * of overload ambiguity, since the {@code ArrayList} constructors very wisely did not accept
   * varargs.)
   *
   * @param initialArraySize the exact size of the initial backing array for the returned array list
   *     ({@code ArrayList} documentation calls this value the "capacity")
   * @return a new, empty {@code ArrayList} which is guaranteed not to resize itself unless its size

    assertThat(set).containsExactly("a", "b", "c").inOrder();
  }

  public void testCreation_arrayOfArray() {
    String[] array = new String[] {"a"};
    Set<String[]> set = ImmutableSet.<String[]>of(array);
    assertEquals(Collections.singleton(array), set);
  }

  @GwtIncompatible // ImmutableSet.chooseTableSize
  public void testChooseTableSize() {

    return snapshot().toArray();
  }

  @Override
  @SuppressWarnings("nullness") // b/192354773 in our checker affects toArray declarations
  public <T extends @Nullable Object> T[] toArray(T[] array) {
    return snapshot().toArray(array);
  }

  /*
   * We'd love to use 'new ArrayList(this)' or 'list.addAll(this)', but
   * either of these would recurse back to us again!
   */
  private List<E> snapshot() {