PeekingIterator<?> peekingIterator = Iterators.peekingIterator(iterator);

    assertThrows(NoSuchElementException.class, () -> peekingIterator.peek());
  }

  public void testPeekDoesntChangeIteration() {
    List<?> list = Lists.newArrayList("A", "B", "C");
    Iterator<?> iterator = list.iterator();
    PeekingIterator<?> peekingIterator = Iterators.peekingIterator(iterator);