return new RegularImmutableList<>(elementsWithoutTrailingNulls);
    }
  }

  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);
  }

        @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();
        }
      };

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

        Iterators.advance(iterator, numberToSkip);

        /*

    }
  }

  /**
   * Verifies that an Iterator is unmodifiable.
   *
   * <p>This test only works with iterators that iterate over a finite set.
   */
  public static void assertIteratorIsUnmodifiable(Iterator<?> iterator) {
    while (iterator.hasNext()) {
      iterator.next();
      try {
        iterator.remove();
        fail("Remove on unmodifiable iterator succeeded");

  }

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

  }

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

      iterator.remove();
    }
  }

  /** ValueIterator build on top of EntryIterator. */
  final class ValueIterator implements Iterator<V> {
    private EntryIterator iterator;

    ValueIterator() {
      iterator = new EntryIterator();
    }

    @Override
    public boolean hasNext() {
      return iterator.hasNext();
    }

    @Override
    public V next() {

      }

      @Override
      Iterator<E> elementIterator() {
        throw new AssertionError("should never be called");
      }

      @Override
      Iterator<Entry<E>> entryIterator() {
        final Iterator<? extends Entry<? extends E>> iterator1 = multiset1.entrySet().iterator();
        final Iterator<? extends Entry<? extends E>> iterator2 = multiset2.entrySet().iterator();

    }

    @Override
    public boolean isEmpty() {
      return !Iterables.any(unfiltered, predicate);
    }

    @Override
    public Iterator<E> iterator() {
      return Iterators.filter(unfiltered.iterator(), predicate);
    }

    @Override
    public Spliterator<E> spliterator() {
      return CollectSpliterators.filter(unfiltered.spliterator(), predicate);
    }

   */
  public static <T extends @Nullable Object> boolean isInOrder(
      Iterable<? extends T> iterable, Comparator<T> comparator) {
    checkNotNull(comparator);
    Iterator<? extends T> it = iterable.iterator();
    if (it.hasNext()) {
      T prev = it.next();
      while (it.hasNext()) {
        T next = it.next();
        if (comparator.compare(prev, next) > 0) {
          return false;
        }