* returns a new instance.
 *
 * This collection is optimized for safe concurrent access over a very small number of elements.
 *
 * This collection and is expected to hold fewer than 10 elements. Each operation is _O(N)_, and so
 * building an instance with _N_ elements is _O(N**2)_.
 */
internal sealed class Tags {
  /**
   * Returns a tags instance that maps [key] to [value]. If [value] is null, this returns a tags

  }

  public static class Chars extends SampleElements<Character> {
    public Chars() {
      // elements aren't sorted, to better test SortedSet iteration ordering
      super('b', 'a', 'c', 'd', 'e');
    }
  }

  public static class Enums extends SampleElements<AnEnum> {
    public Enums() {
      // elements aren't sorted, to better test SortedSet iteration ordering
      super(AnEnum.B, AnEnum.A, AnEnum.C, AnEnum.D, AnEnum.E);

 * </ul>
 *
 * <h4>Full Inference for 4.1.0+ Models</h4>
 * <ul>
 *   <li><strong>ModelVersion Removal</strong>: Removes {@code <modelVersion>} element (inference enabled)</li>
 *   <li><strong>Root Attribute</strong>: Adds {@code root="true"} attribute to root project</li>
 *   <li><strong>Parent Element Trimming</strong>:
 *     <ul>
 *       <li>Removes parent {@code <groupId>} when child has no explicit groupId</li>

    suite.addTest(
        NavigableSetTestSuiteBuilder.using(
                new TestStringSetGenerator() {
                  @Override
                  protected Set<String> create(String[] elements) {
                    return new SafeTreeSet<>(asList(elements));
                  }

                  @Override
                  public List<String> order(List<String> insertionOrder) {

    ms.add("b", 2);
    SortedSet<String> elementSet = ms.elementSet();

    assertEquals("a", elementSet.first());
    assertEquals("c", elementSet.last());
    assertEquals(Ordering.natural(), elementSet.comparator());

    assertThat(elementSet.headSet("b")).containsExactly("a");
    assertThat(elementSet.tailSet("b")).containsExactly("b", "c").inOrder();
    assertThat(elementSet.subSet("a", "c")).containsExactly("a", "b").inOrder();

    return new Ints();
  }

  @Override
  public Set<Integer> create(Object... elements) {
    Integer[] array = new Integer[elements.length];
    int i = 0;
    for (Object e : elements) {
      array[i++] = (Integer) e;
    }
    return create(array);
  }

  protected abstract Set<Integer> create(Integer[] elements);

  @Override
  public Integer[] createArray(int length) {
    return new Integer[length];

 * elementsToInsert}, the elements to be passed to {@code set()} and {@code add()} calls; {@code
 * features}, the features supported by the iterator; and {@code expectedElements}, the elements the
 * iterator should return in order.
 *
 * <p>The items in {@code elementsToInsert} will be repeated if {@code steps} is larger than the
 * number of provided elements.
 *
 * @author Chris Povirk
 */
@GwtCompatible

    assertTrue(
        ((RegularImmutableList<String>)
                    ((RegularImmutableSortedMultiset<String>) multiset1).elementSet.elements)
                .array
            != builder.elements);
  }

  public void testBuilderAddAll() {
    List<String> a = asList("a", "b");
    List<String> b = asList("c", "d");
    ImmutableSortedMultiset<String> multiset =

        SetTestSuiteBuilder.using(
                new TestStringSetGenerator() {
                  @Override
                  protected Set<String> create(String[] elements) {
                    return new StandardImplForwardingSet<>(new LinkedHashSet<>(asList(elements)));
                  }
                })
            .named("ForwardingSet[LinkedHashSet] with standard implementations")
            .withFeatures(

 * both {@link Collection} and {@link Map}; since there isn't an established collective noun that
 * encompasses both of these, 'container' is used.
 *
 * @author George van den Driessche
 */
@GwtCompatible
@NullMarked
public interface TestContainerGenerator<T, E extends @Nullable Object> {
  /** Returns the sample elements that this generate populates its container with. */