assertEquals("b", iterator.previous());
    assertThrows(UnsupportedOperationException.class, () -> iterator.add("c"));
  }

  @SuppressWarnings("DoNotCall")
  public void testSet() {
    ListIterator<String> iterator = create();

    assertTrue(iterator.hasNext());
    assertEquals("a", iterator.next());
    assertEquals("b", iterator.next());
    assertEquals("b", iterator.previous());

   *     iterator().next()} or {@link Iterables#getFirst} instead.
   */
  @SuppressWarnings("nullness") // Unsafe, but we can't do much about it now.
  public final Optional<@NonNull E> first() {
    Iterator<E> iterator = getDelegate().iterator();
    return iterator.hasNext() ? Optional.of(iterator.next()) : Optional.absent();
  }

  /**

    return (MinimalIterable) of(elements.toArray());
  }

  private @Nullable Iterator<E> iterator;

  private MinimalIterable(Iterator<E> iterator) {
    this.iterator = iterator;
  }

  @Override
  public Iterator<E> iterator() {
    if (iterator == null) {
      // TODO: throw something else? Do we worry that people's code and tests

    }
    try {
      Iterator<Integer> iterator = unmod.iterator();
      iterator.next();
      iterator.remove();
      fail("UnsupportedOperationException expected");
    } catch (UnsupportedOperationException expected) {
    }
    try {
      Iterator<Integer> iterator = unmod.descendingIterator();
      iterator.next();
      iterator.remove();

  public void testRemoveIfSomeMatchesConcurrentWithIteration() {
    assertThrows(
        ConcurrentModificationException.class,
        () -> {
          Iterator<E> iterator = collection.iterator();
          assertTrue(collection.removeIf(Predicate.isEqual(samples.e0())));
          iterator.next();
        });
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)

  public void testRemoveAtIndexConcurrentWithIteration() {
    assertThrows(
        ConcurrentModificationException.class,
        () -> {
          Iterator<E> iterator = collection.iterator();
          getList().remove(getNumElements() / 2);
          iterator.next();
        });
  }

  @ListFeature.Require(SUPPORTS_REMOVE_WITH_INDEX)
  @CollectionSize.Require(absent = ZERO)
  public void testRemoveAtIndex_last() {

      @Override
      public Iterator<T> iterator() {
        if (iterable instanceof List) {
          List<T> list = (List<T>) iterable;
          int toSkip = Math.min(list.size(), numberToSkip);
          return list.subList(toSkip, list.size()).iterator();
        }
        Iterator<T> iterator = iterable.iterator();

        Iterators.advance(iterator, numberToSkip);

        /*

    public E element() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.element();
    }

    @Override
    public Iterator<E> iterator() {
      // We explicitly don't lock for iterator()
      assertFalse(Thread.holdsLock(mutex));
      return delegate.iterator();
    }

    @Override
    public int size() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.size();
    }

   *     iterator().next()} or {@link Iterables#getFirst} instead.
   */
  @SuppressWarnings("nullness") // Unsafe, but we can't do much about it now.
  public final Optional<@NonNull E> first() {
    Iterator<E> iterator = getDelegate().iterator();
    return iterator.hasNext() ? Optional.of(iterator.next()) : Optional.absent();
  }

  /**

        @Override
        public @Nullable Object execute(Iterator<?> iterator) {
          iterator.remove();
          return null;
        }
      };

  private static final IteratorOperation NEXT_METHOD =
      new IteratorOperation() {
        @Override
        public @Nullable Object execute(Iterator<?> iterator) {
          return iterator.next();
        }
      };