/**
 * A non-blocking queue which automatically evicts elements from the head of the queue when
 * attempting to add new elements onto the queue and it is full. This queue orders elements FIFO
 * (first-in-first-out). This data structure is logically equivalent to a circular buffer (i.e.,
 * cyclic buffer or ring buffer).
 *
 * <p>An evicting queue must be configured with a maximum size. Each time an element is added to a

              protected List<String> create(String[] elements) {
                return new AbstractList<String>() {
                  @Override
                  public int size() {
                    return elements.length;
                  }

                  @Override
                  public String get(int index) {
                    return elements[index];
                  }
                };

  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(

    // 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.

    final BlockingQueue<Object> q;
    final int elements;
    final CountDownLatch beganProducing = new CountDownLatch(1);
    final CountDownLatch doneProducing = new CountDownLatch(1);

    Producer(BlockingQueue<Object> q, int elements) {
      this.q = q;
      this.elements = elements;
    }

    @Override
    public @Nullable Void call() throws InterruptedException {

    }

    @Override
    public Set<E> create(Object... elements) {
      Object[] duplicated = new Object[elements.length * 2];
      for (int i = 0; i < elements.length; i++) {
        duplicated[i] = elements[i];
        duplicated[i + elements.length] = elements[i];
      }
      return ((Multiset<E>) gen.create(duplicated)).elementSet();
    }

    @Override
    public E[] createArray(int length) {

    return new Strings();
  }

  @Override
  public Multiset<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 Multiset<String> create(String[] elements);

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

      Table<String, Integer, Character> table, String[] elements) {
    for (String row : elements) {
      table.put(row, 1, 'a');
      table.put(row, 2, 'b');
    }
  }

  private static void populateForColumnKeySet(
      Table<Integer, String, Character> table, String[] elements) {
    for (String column : elements) {
      table.put(1, column, 'a');
      table.put(2, column, 'b');
    }

        Multiset<String> multiset1 = LinkedHashMultiset.create();
        Multiset<String> multiset2 = LinkedHashMultiset.create();
        multiset1.add("only1");
        multiset2.add("only2");
        for (int i = 0; i < elements.length; i++) {
          multiset1.add(elements[i]);
          multiset2.add(elements[elements.length - 1 - i]);
        }
        if (elements.length > 0) {

   * which the elements appear in the given collection.
   *
   * @param elements the elements, all of the same {@code enum} type, that the set should contain
   * @return an immutable set containing those elements, minus duplicates
   */
  public static <E extends Enum<E>> ImmutableSet<E> immutableEnumSet(Iterable<E> elements) {
    if (elements instanceof ImmutableEnumSet) {