* 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

  /*
   * We are currently considering the elements in buffer in the range [0, bufferSize) as candidates
   * for the top k elements. Whenever the buffer is filled, we quickselect the top k elements to the
   * range [0, k) and ignore the remaining elements.
   */
  private final @Nullable T[] buffer;
  private int bufferSize;

  /**
   * The largest of the lowest k elements we've seen so far relative to this comparator. If

  public void testHashCode() {
    int expectedHashCode = 1;
    for (E element : getOrderedElements()) {
      expectedHashCode = 31 * expectedHashCode + ((element == null) ? 0 : element.hashCode());
    }
    assertEquals(
        "A List's hashCode() should be computed from those of its elements.",
        expectedHashCode,
        getList().hashCode());
  }

  /**

      return samples;
    }

    @Override
    public Set<K> create(Object... elements) {
      @SuppressWarnings("unchecked")
      K[] keysArray = (K[]) elements;

      // Start with a suitably shaped collection of entries
      Collection<Entry<K, V>> originalEntries = mapGenerator.getSampleElements(elements.length);

      // Create a copy of that, with the desired value for each key

    return new Chars();
  }

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

  /**
   * Creates a new collection containing the given elements; implement this method instead of {@link
   * #create(Object...)}.
   */

    return new Strings();
  }

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

  /**
   * Creates a new collection containing the given elements; implement this method instead of {@link
   * #create(Object...)}.
   */

    this.equivalence = checkNotNull(equivalence);
  }

  /**
   * Different orderings for combining the elements of an input array, which must all produce the
   * same result.
   */
  enum CollectStrategy {
    /** Get one accumulator and accumulate the elements into it sequentially. */
    SEQUENTIAL {
      @Override

      return samples;
    }

    @Override
    public Set<K> create(Object... elements) {
      @SuppressWarnings("unchecked")
      K[] keysArray = (K[]) elements;

      // Start with a suitably shaped collection of entries
      Collection<Entry<K, V>> originalEntries = mapGenerator.getSampleElements(elements.length);

      // Create a copy of that, with the desired value for each key

  public SampleElements<Entry<K, V>> samples() {
    return SampleElements.mapEntries(keys, values);
  }

  @Override
  public Set<Entry<K, V>> create(Object... elements) {
    Entry<K, V>[] entries = createArray(elements.length);
    arraycopy(elements, 0, entries, 0, elements.length);
    return createFromEntries(entries);
  }

  public abstract Set<Entry<K, V>> createFromEntries(Entry<K, V>[] entries);

  @Override

    return new Strings();
  }

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

  protected abstract Collection<String> create(String[] elements);

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