StringSubscriber s2 = new StringSubscriber();
    ObjectSubscriber o1 = new ObjectSubscriber();

    Iterator<Subscriber> empty = registry.getSubscribers("");
    assertFalse(empty.hasNext());

    empty = registry.getSubscribers("");

    registry.register(s1);
    assertFalse(empty.hasNext());

    Iterator<Subscriber> one = registry.getSubscribers("");
    assertEquals(s1, one.next().target);

        } catch (NullPointerException | ClassCastException e) {
          return false;
        }
      }

      @Override
      public Iterator<Entry<K, V>> iterator() {
        return delegate().iterator();
      }

      @Override
      public int size() {
        return delegate().size();
      }

      @Override
      public boolean remove(Object o) {

    }
    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);
  }

    assertThrows(
        ConcurrentModificationException.class,
        () -> {
          Iterator<Entry<K, V>> iterator = getMap().entrySet().iterator();
          putAll(MinimalCollection.of(e3(), e0()));
          iterator.next();
        });
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)

   *     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();

   * analogous operation with swapped rows and columns. For example, in a {@link HashBasedTable}
   * instance, {@code rowKeySet().iterator()} supports {@code remove()} but {@code
   * columnKeySet().iterator()} doesn't. With a transposed {@link HashBasedTable}, it's the other
   * way around.
   */
  public static <R extends @Nullable Object, C extends @Nullable Object, V extends @Nullable Object>

    return delegate.higher(checkValid(e));
  }

  @Override
  public boolean isEmpty() {
    return delegate.isEmpty();
  }

  @Override
  public Iterator<E> iterator() {
    return delegate.iterator();
  }

  @Override
  public E last() {
    return delegate.last();
  }

  @Override
  public @Nullable E lower(E e) {
    return delegate.lower(checkValid(e));
  }

  public SampleElements(E e0, E e1, E e2, E e3, E e4) {
    this.e0 = e0;
    this.e1 = e1;
    this.e2 = e2;
    this.e3 = e3;
    this.e4 = e4;
  }

  @Override
  public Iterator<E> iterator() {
    return asList().iterator();
  }

  public List<E> asList() {
    return Arrays.asList(e0(), e1(), e2(), e3(), e4());
  }

  public static class Strings extends SampleElements<String> {
    public Strings() {

        // When
        mockIterator.close();

        // Then
        verify(mockIterator).close();
    }

    @Test
    @DisplayName("Should extend Iterator and AutoCloseable")
    void testInterfaceInheritance() {
        // Then
        assertTrue(java.util.Iterator.class.isAssignableFrom(CloseableIterator.class));
        assertTrue(AutoCloseable.class.isAssignableFrom(CloseableIterator.class));
    }

  }

  @CollectionSize.Require(ONE)
  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
  public void testKeysEntrySetIteratorRemove() {
    Multiset<K> keys = multimap().keys();
    Iterator<Multiset.Entry<K>> itr = keys.entrySet().iterator();
    assertEquals(Multisets.immutableEntry(k0(), 1), itr.next());
    itr.remove();
    assertTrue(multimap().isEmpty());
  }

  @CollectionSize.Require(SEVERAL)