}
  }

  public void testSize0() {
    Iterator<String> iterator = Iterators.emptyIterator();
    assertEquals(0, Iterators.size(iterator));
  }

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

  public void testSize_partiallyConsumed() {

  }

  public void testNewEnumSet_collection() {
    Set<SomeEnum> set = ImmutableSet.of(SomeEnum.B, SomeEnum.C);
    assertEquals(set, newEnumSet(set, SomeEnum.class));
  }

  public void testNewEnumSet_iterable() {
    Set<SomeEnum> set = ImmutableSet.of(SomeEnum.A, SomeEnum.B, SomeEnum.C);
    assertEquals(set, newEnumSet(unmodifiableIterable(set), SomeEnum.class));
  }

  public void testNewHashSetEmpty() {

 *
 * <pre>{@code
 * public static double sqrt(double value) {
 *   if (value < 0) {
 *     throw new IllegalArgumentException("input is negative: " + value);
 *   }
 *   // calculate square root
 * }
 * }</pre>
 *
 * <p>to be replaced with the more compact
 *
 * <pre>{@code
 * public static double sqrt(double value) {

  public K ceilingKey(K key) {
    return keyOrNull(ceilingEntry(key));
  }

  @Override
  @CheckForNull
  public Entry<K, V> higherEntry(K key) {
    return tailMap(key, false).firstEntry();
  }

  @Override
  @CheckForNull
  public K higherKey(K key) {
    return keyOrNull(higherEntry(key));
  }

  @Override
  @CheckForNull
  public Entry<K, V> firstEntry() {

    }

    @Override
    public boolean add(E e) {
      synchronized (mutex) {
        return delegate().add(e);
      }
    }

    @Override
    public boolean addAll(Collection<? extends E> c) {
      synchronized (mutex) {
        return delegate().addAll(c);
      }
    }

    @Override
    public void clear() {
      synchronized (mutex) {

    }

    @Override
    public final boolean isDone() {
      return super.isDone();
    }

    @Override
    public final boolean isCancelled() {
      return super.isCancelled();
    }

    @Override
    public final void addListener(Runnable listener, Executor executor) {
      super.addListener(listener, executor);
    }

    @CanIgnoreReturnValue
    @Override

    @CheckForNull
    public E higher(@ParametricNullness E e) {
      return forward.lower(e);
    }

    @Override
    @CheckForNull
    public E pollFirst() {
      return forward.pollLast();
    }

    @Override
    @CheckForNull
    public E pollLast() {
      return forward.pollFirst();
    }

    @Override
    public NavigableSet<E> descendingSet() {

    }

    @Override
    public DummyInternalEntry getNext() {
      throw new AssertionError();
    }

    @Override
    public int getHash() {
      throw new AssertionError();
    }

    @Override
    public Object getKey() {
      throw new AssertionError();
    }

    @Override
    public Object getValue() {
      throw new AssertionError();

    }
  }

  public void testSize0() {
    Iterator<String> iterator = Iterators.emptyIterator();
    assertEquals(0, Iterators.size(iterator));
  }

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

  public void testSize_partiallyConsumed() {

      return result;
    }

    @Override
    public boolean put(@ParametricNullness K key, @ParametricNullness V value) {
      throw new UnsupportedOperationException();
    }

    @Override
    public boolean putAll(@ParametricNullness K key, Iterable<? extends V> values) {
      throw new UnsupportedOperationException();
    }

    @Override
    public boolean putAll(Multimap<? extends K, ? extends V> multimap) {