public T next() {
      if (!hasNext()) {
        throw new NoSuchElementException();
      }
      T result = result(entryIndex);
      toRemove = entryIndex;
      entryIndex = backingMap.nextIndex(entryIndex);
      return result;
    }

    @Override
    public void remove() {
      checkForConcurrentModification();
      CollectPreconditions.checkRemove(toRemove != -1);

      @Override
      @ParametricNullness
      public V previous() {
        return getDelegateListIterator().previous();
      }

      @Override
      public int nextIndex() {
        return getDelegateListIterator().nextIndex();
      }

      @Override
      public int previousIndex() {
        return getDelegateListIterator().previousIndex();
      }

      @Override

  public void testEmptyListIterator() {
    ListIterator<String> iterator = Iterators.emptyListIterator();
    assertFalse(iterator.hasNext());
    assertFalse(iterator.hasPrevious());
    assertEquals(0, iterator.nextIndex());
    assertEquals(-1, iterator.previousIndex());
    assertThrows(NoSuchElementException.class, () -> iterator.next());
    assertThrows(NoSuchElementException.class, () -> iterator.previous());