assertThat(it.hasNext(), is(true));
        assertThat(it.next(), is("Foo"));

        assertThat(it.hasNext(), is(true));
        assertThat(it.next(), is("Bar"));

        assertThat(it.hasNext(), is(true));
        assertThat(it.next(), is("Baz"));

        assertThat(it.hasNext(), is(not(true)));
    }

      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
      T result = checkNotNull(itr.next());
      if (!itr.hasNext()) {
        stack.removeLast();
      }
      Iterator<T> childItr = children(result).iterator();

        return null;
    }

    protected abstract SmbResource adapt(FileEntry e) throws MalformedURLException;

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

    /**
     * {@inheritDoc}
     *
     * @see java.util.Iterator#next()
     */
    @Override

    assertFalse(iterator.hasNext());
    assertThrows(NoSuchElementException.class, () -> iterator.next());
    assertThrows(IllegalStateException.class, () -> iterable.iterator());
  }

  public void testOf_one() {
    Iterable<String> iterable = MinimalIterable.of("a");
    Iterator<String> iterator = iterable.iterator();
    assertTrue(iterator.hasNext());
    assertEquals("a", iterator.next());

        this.iterators = iterators;
    }

    @Override
    public boolean hasNext() {
        for (; index < iterators.length; ++index) {
            if (iterators[index].hasNext()) {
                return true;
            }
        }
        return false;
    }

    @Override
    public E next() {
        if (!hasNext()) {
            throw new NoSuchElementException();
        }

    Iterator<Entry<K, Collection<V>>> entryIterator = unfiltered.asMap().entrySet().iterator();
    boolean changed = false;
    while (entryIterator.hasNext()) {
      Entry<K, Collection<V>> entry = entryIterator.next();
      K key = entry.getKey();
      Collection<V> collection = filterCollection(entry.getValue(), new ValuePredicate(key));
      if (!collection.isEmpty()

          Set<N> seenNodes = new HashSet<>();
          return new AbstractIterator<N>() {
            @Override
            protected @Nullable N computeNext() {
              while (nodeConnections.hasNext()) {
                NodeConnection<N> nodeConnection = nodeConnections.next();
                boolean added = seenNodes.add(nodeConnection.node);
                if (added) {
                  return nodeConnection.node;

    abstract T output(@ParametricNullness K key, @ParametricNullness V value);

    @Override
    public boolean hasNext() {
      return keyIterator.hasNext() || valueIterator.hasNext();
    }

    @Override
    @ParametricNullness
    public T next() {
      if (!valueIterator.hasNext()) {
        Entry<K, Collection<V>> mapEntry = keyIterator.next();
        key = mapEntry.getKey();

    assertEquals(rangeSet.asDescendingSetOfRanges().isEmpty(), rangeSet.isEmpty());
    assertEquals(!rangeSet.asRanges().iterator().hasNext(), rangeSet.isEmpty());
    assertEquals(!rangeSet.asDescendingSetOfRanges().iterator().hasNext(), rangeSet.isEmpty());

    List<Range<C>> asRanges = ImmutableList.copyOf(rangeSet.asRanges());

    // test that connected ranges are coalesced

    @Override
    public void execute(Runnable command) {
      tasks.add(command);
    }

    boolean hasNext() {
      return !tasks.isEmpty();
    }

    void runNext() {
      assertTrue("expected at least one task to run", hasNext());
      tasks.remove().run();
    }

    void runAll() {
      while (hasNext()) {
        runNext();
      }
    }
  }

  private FakeExecutor fakePool;