}
  }

  /**
   * 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");

 * target iterators on demand. It also requires three additional constructor parameters: {@code
 * elementsToInsert}, the elements to be passed to {@code set()} and {@code add()} calls; {@code
 * features}, the features supported by the iterator; and {@code expectedElements}, the elements the
 * iterator should return in order.
 *

  public void testCopyOf_iterator_empty() {
    Iterator<String> iterator = Iterators.emptyIterator();
    Multiset<String> multiset = ImmutableSortedMultiset.copyOf(iterator);
    assertTrue(multiset.isEmpty());
  }

  public void testCopyOf_iterator_oneElement() {
    Iterator<String> iterator = Iterators.singletonIterator("a");
    Multiset<String> multiset = ImmutableSortedMultiset.copyOf(iterator);

          @Override
          public Iterator<Entry<Range<K>, V>> iterator() {
            return entryIterator();
          }

          @Override
          public boolean retainAll(Collection<?> c) {
            return removeEntryIf(not(in(c)));
          }

          @Override
          public int size() {
            return Iterators.size(iterator());
          }

          @Override

        return new AbstractSet<EndpointPair<N>>() {
          @Override
          public Iterator<EndpointPair<N>> iterator() {
            return Iterators.transform(
                AbstractNetwork.this.edges().iterator(), edge -> incidentNodes(edge));
          }

          @Override
          public int size() {
            return AbstractNetwork.this.edges().size();

        return new AbstractSet<EndpointPair<N>>() {
          @Override
          public Iterator<EndpointPair<N>> iterator() {
            return Iterators.transform(
                AbstractNetwork.this.edges().iterator(), edge -> incidentNodes(edge));
          }

          @Override
          public int size() {
            return AbstractNetwork.this.edges().size();

    private final Collection<ToolingModelBuilder> builders = new AbstractCollection<ToolingModelBuilder>() {
        @Override
        public Iterator<ToolingModelBuilder> iterator() {
            return Iterators.transform(registrations.iterator(), RegistrationImpl::getBuilder);
        }

        @Override
        public int size() {
            return registrations.size();
        }
    };

        return set1.isEmpty() && set2.isEmpty();
      }

      @Override
      public UnmodifiableIterator<E> iterator() {
        return new AbstractIterator<E>() {
          final Iterator<? extends E> itr1 = set1.iterator();
          final Iterator<? extends E> itr2 = set2.iterator();

          @Override
          @CheckForNull
          protected E computeNext() {
            if (itr1.hasNext()) {

  public void testCopyOf_iterator_empty() {
    Iterator<String> iterator = Iterators.emptyIterator();
    Multiset<String> multiset = ImmutableSortedMultiset.copyOf(iterator);
    assertTrue(multiset.isEmpty());
  }

  public void testCopyOf_iterator_oneElement() {
    Iterator<String> iterator = Iterators.singletonIterator("a");
    Multiset<String> multiset = ImmutableSortedMultiset.copyOf(iterator);

        return set1.isEmpty() && set2.isEmpty();
      }

      @Override
      public UnmodifiableIterator<E> iterator() {
        return new AbstractIterator<E>() {
          final Iterator<? extends E> itr1 = set1.iterator();
          final Iterator<? extends E> itr2 = set2.iterator();

          @Override
          @CheckForNull
          protected E computeNext() {
            if (itr1.hasNext()) {