@Override
      protected Iterator<Integer> newTargetIterator() {
        return Iterators.forArray(1, 2, 3);
      }
    }.test();
  }

  /*
   * TODO(cpovirk): Test forArray with ListIteratorTester (not just IteratorTester), including with
   * a start position other than 0.
   */

  public void testForEnumerationEmpty() {

      @Override
      protected Iterator<Integer> newTargetIterator() {
        return Iterators.forArray(1, 2, 3);
      }
    }.test();
  }

  /*
   * TODO(cpovirk): Test forArray with ListIteratorTester (not just IteratorTester), including with
   * a start position other than 0.
   */

  public void testForEnumerationEmpty() {

  }

  public void testCopyOf_iterator_oneElementRepeated() {
    Iterator<String> iterator = Iterators.forArray("a", "a", "a");
    Set<String> set = copyOf(iterator);
    assertEquals(singleton("a"), set);
  }

  public void testCopyOf_iterator_general() {
    Iterator<String> iterator = Iterators.forArray("a", "b", "a");
    Set<String> set = copyOf(iterator);
    assertEquals(2, set.size());

  // (In the backport, we don't need this suppression, but we keep it to minimize diffs.)
  @SuppressWarnings("unchecked")
  @Override
  public UnmodifiableIterator<E> iterator() {
    return (UnmodifiableIterator<E>) Iterators.forArray(elements);
  }

  @Override
  public Spliterator<E> spliterator() {
    return Spliterators.spliterator(elements, SPLITERATOR_CHARACTERISTICS);
  }

  @Override
  Object[] internalArray() {

   */
  public abstract boolean isOrdered();

  /** Iterates in the order {@link #nodeU()}, {@link #nodeV()}. */
  @Override
  public final UnmodifiableIterator<N> iterator() {
    return Iterators.forArray(nodeU, nodeV);
  }

  /**
   * Two ordered {@link EndpointPair}s are equal if their {@link #source()} and {@link #target()}

  }

  public void testLeastOfIterator_simple_negativeOne() {
    assertThrows(
        IllegalArgumentException.class,
        () -> numberOrdering.leastOf(Iterators.forArray(3, 4, 5, -1), -1));
  }

  public void testLeastOfIterable_singleton_0() {
    List<Integer> result = numberOrdering.leastOf(asList(3), 0);
    assertTrue(result instanceof RandomAccess);

  }

  public void testLeastOfIterator_simple_negativeOne() {
    assertThrows(
        IllegalArgumentException.class,
        () -> numberOrdering.leastOf(Iterators.forArray(3, 4, 5, -1), -1));
  }

  public void testLeastOfIterable_singleton_0() {
    List<Integer> result = numberOrdering.leastOf(asList(3), 0);
    assertTrue(result instanceof RandomAccess);