assertEquals("Should have removed an element", 2, list.size());
    assertFalse("Second element should be gone", list.contains("B"));
  }

  static class ThrowsAtEndException extends RuntimeException {
    /* nothing */
  }

  /**
   * This Iterator claims to have more elements than the underlying iterable, but when you try to
   * fetch the extra elements, it throws an unchecked exception.
   */

   * elements.
   */
  @SafeVarargs
  public static <T extends @Nullable Object> Iterator<T> cycle(T... elements) {
    return cycle(Lists.newArrayList(elements));
  }

  /**
   * Returns an Iterator that walks the specified array, nulling out elements behind it. This can
   * avoid memory leaks when an element is no longer necessary.
   *

   * elements.
   */
  @SafeVarargs
  public static <T extends @Nullable Object> Iterator<T> cycle(T... elements) {
    return cycle(Lists.newArrayList(elements));
  }

  /**
   * Returns an Iterator that walks the specified array, nulling out elements behind it. This can
   * avoid memory leaks when an element is no longer necessary.
   *

    E[] elements = createSamplesArray();
    E duplicate = elements[(elements.length / 2) - 1];
    elements[(elements.length / 2) + 1] = duplicate;
    return new ArrayWithDuplicate<>(elements, duplicate);
  }

  // Helper methods to improve readability of derived classes

  protected int getNumElements() {
    return getSubjectGenerator().getCollectionSize().getNumElements();
  }

  public void testHashCode_containingNull() {
    Collection<E> elements = getSampleElements(getNumElements() - 1);
    int expectedHashCode = 0;
    for (E element : elements) {
      expectedHashCode += (element == null) ? 0 : element.hashCode();
    }

    elements.add(null);
    collection = getSubjectGenerator().create(elements.toArray());
    assertEquals(

    }

    @Override
    public boolean add(@ParametricNullness E element) {
      checkArgument(predicate.apply(element));
      return unfiltered.add(element);
    }

    @Override
    public boolean addAll(Collection<? extends E> collection) {
      for (E element : collection) {
        checkArgument(predicate.apply(element));
      }
      return unfiltered.addAll(collection);
    }

   * default initial capacity, load factor, and concurrency settings.
   *
   * <p>This implementation is highly efficient when {@code elements} is itself a {@link Multiset}.
   *
   * @param elements the elements that the multiset should contain
   */
  public static <E> ConcurrentHashMultiset<E> create(Iterable<? extends E> elements) {

    // We special-case for 0 or 1 elements, but going further is madness.
    if (!elements.hasNext()) {
      return of();
    }
    E first = elements.next();
    if (!elements.hasNext()) {
      return of(first);
    } else {
      return new ImmutableList.Builder<E>().add(first).addAll(elements).build();
    }
  }

  /**
   * Returns an immutable list containing the given elements, in order.

 *   <li>{@code merge} (default): Merges elements with matching names</li>
 *   <li>{@code append}: Adds elements as siblings</li>
 * </ul>
 *
 * <p>Self combination modes (specified by {@code combine.self} attribute):</p>
 * <ul>
 *   <li>{@code merge} (default): Merges attributes and values</li>
 *   <li>{@code override}: Completely replaces the element</li>
 *   <li>{@code remove}: Removes the element</li>
 * </ul>
 *

    }

    /**
     * Adds an element to the beginning of a sequenced collection.
     *
     * @param <E> the element type
     * @param collection the sequenced collection
     * @param element the element to add
     * @since Java 21
     */
    public static <E> void addFirst(final SequencedCollection<E> collection, final E element) {
        collection.addFirst(element);
    }

    /**