@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 void testSize1() {
    Iterator<Integer> iterator = singleton(0).iterator();
    assertEquals(1, Iterators.size(iterator));
  }

  public void testSize_partiallyConsumed() {
    Iterator<Integer> iterator = asList(1, 2, 3, 4, 5).iterator();
    iterator.next();
    iterator.next();
    assertEquals(3, Iterators.size(iterator));
  }

      return !stack.isEmpty();
    }

    @Override
    public T next() {
      Iterator<T> itr = stack.getLast(); // throws NSEE if empty
      T result = checkNotNull(itr.next());
      if (!itr.hasNext()) {
        stack.removeLast();
      }
      Iterator<T> childItr = children(result).iterator();
      if (childItr.hasNext()) {
        stack.addLast(childItr);
      }
      return result;

        }
    }

    /**
     * {@inheritDoc}
     *
     * @see java.util.Iterator#hasNext()
     */
    @Override
    public boolean hasNext() {
        return this.next != null;
    }

    /**
     * {@inheritDoc}
     *
     * @see java.util.Iterator#next()
     */
    @Override
    public FileEntry next() {
        final FileEntry n = this.next;

    private final Deque<Iterator<T>> stack;

    PreOrderIterator(T root) {
      this.stack = new ArrayDeque<>();
      stack.addLast(singletonIterator(checkNotNull(root)));
    }

    @Override
    public boolean hasNext() {
      return !stack.isEmpty();
    }

    @Override
    public T next() {
      Iterator<T> itr = stack.getLast(); // throws NSEE if empty

      @Override
      public Iterator<T> iterator() {
        return Iterators.concat(
            /* lazily generate the iterators on each input only as needed */
            new AbstractIndexedListIterator<Iterator<? extends T>>(inputs.length) {
              @Override
              public Iterator<? extends T> get(int i) {
                return inputs[i].iterator();
              }
            });
      }

      @Override
      public Iterator<T> iterator() {
        return Iterators.concat(
            /* lazily generate the iterators on each input only as needed */
            new AbstractIndexedListIterator<Iterator<? extends T>>(inputs.length) {
              @Override
              public Iterator<? extends T> get(int i) {
                return inputs[i].iterator();
              }
            });
      }

        @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();
        }
      };

    public String toString() {
        StringBuilder ret = new StringBuilder().append(proto).append(":").append(server).append("[").append(endpoint);
        if (options != null) {
            final Iterator iter = options.keySet().iterator();
            while (iter.hasNext()) {
                final Object key = iter.next();
                final Object val = options.get(key);

    }
  }

  /**
   * 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");