assertEquals(3, (int) enumer.nextElement());
    assertFalse(enumer.hasMoreElements());
  }

  // We're testing our asEnumeration method against a known-good implementation.
  @SuppressWarnings("JdkObsolete")
  private static Enumeration<Integer> enumerate(int... ints) {
    Vector<Integer> vector = new Vector<>(Ints.asList(ints));
    return vector.elements();
  }

  public void testToString() {

   * you have a {@link Collection}), or {@code Iterators.asEnumeration(collection.iterator())}.
   */
  // This is an adapter for cases in which users do need an Enumeration for whatever reason.
  @SuppressWarnings("JdkObsolete")
  public static <T extends @Nullable Object> Enumeration<T> asEnumeration(Iterator<T> iterator) {
    checkNotNull(iterator);
    return new Enumeration<T>() {
      @Override