* queue's iterator:
   *
   * <pre>{@code
   * Queue<E> queue = Queues.synchronizedQueue(MinMaxPriorityQueue.<E>create());
   * ...
   * queue.add(element);  // Needn't be in synchronized block
   * ...
   * synchronized (queue) {  // Must synchronize on queue!
   *   Iterator<E> i = queue.iterator(); // Must be in synchronized block
   *   while (i.hasNext()) {

      @Override
      public UnmodifiableIterator<E> iterator() {
        Iterable<E> incidentEdges =
            (selfLoopCount == 0)
                ? Iterables.concat(inEdgeMap.keySet(), outEdgeMap.keySet())
                : Sets.union(inEdgeMap.keySet(), outEdgeMap.keySet());
        return Iterators.unmodifiableIterator(incidentEdges.iterator());
      }

      @Override
      public int size() {

 * target iterators on demand. It also requires three additional constructor parameters: {@code
 * 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.
 *

   *     have the same bit length
   */
  public static HashCode combineOrdered(Iterable<HashCode> hashCodes) {
    Iterator<HashCode> iterator = hashCodes.iterator();
    checkArgument(iterator.hasNext(), "Must be at least 1 hash code to combine.");
    int bits = iterator.next().bits();
    byte[] resultBytes = new byte[bits / 8];
    for (HashCode hashCode : hashCodes) {
      byte[] nextBytes = hashCode.asBytes();

  }

  /**
   * Returns a sequential {@link Stream} of the remaining contents of {@code iterator}. Do not use
   * {@code iterator} directly after passing it to this method.
   */
  public static <T extends @Nullable Object> Stream<T> stream(Iterator<T> iterator) {
    return StreamSupport.stream(Spliterators.spliteratorUnknownSize(iterator, 0), false);
  }

  /**

    URL url = getClass().getResource(resourceName);
    for (String line : Resources.readLines(url, UTF_8)) {
      Iterator<String> iterator = splitter.split(line).iterator();
      String input = iterator.next();
      String expectedOutput = iterator.next();
      assertFalse(iterator.hasNext());
      assertEquals(expectedOutput, simplifyPath(input));
    }
  }

    URL url = getClass().getResource(resourceName);
    for (String line : Resources.readLines(url, UTF_8)) {
      Iterator<String> iterator = splitter.split(line).iterator();
      String input = iterator.next();
      String expectedOutput = iterator.next();
      assertFalse(iterator.hasNext());
      assertEquals(expectedOutput, simplifyPath(input));
    }
  }

      return standardSetCount(element, count);
    }

    @Override
    public Set<T> elementSet() {
      return new StandardElementSet();
    }

    @Override
    public Iterator<T> iterator() {
      return standardIterator();
    }

    @Override
    public boolean isEmpty() {
      return standardIsEmpty();
    }

    @Override
    public int size() {

    }
    return new RegularImmutableList<E>(elements, length);
  }

  ImmutableList() {}

  // This declaration is needed to make List.iterator() and
  // ImmutableCollection.iterator() consistent.
  @Override
  public UnmodifiableIterator<E> iterator() {
    return listIterator();
  }

  @Override
  public UnmodifiableListIterator<E> listIterator() {
    return listIterator(0);
  }

  @ParameterizedTest
  @ArgumentsSource(FileSystemParamProvider::class)
  fun iterator(parameters: Pair<FileSystem, Boolean>) {
    setUp(parameters.first, parameters.second)
    set("a", "a1", "a2")
    set("b", "b1", "b2")
    set("c", "c1", "c2")
    val iterator = cache.snapshots()
    assertThat(iterator.hasNext()).isTrue()
    iterator.next().use {
      assertThat(it.key()).isEqualTo("a")