*/
    public IteratorEnumeration(final Iterator<T> iterator) {
        assertArgumentNotNull("iterator", iterator);
        this.iterator = iterator;
    }

    /**
     * Creates an {@link IteratorEnumeration}.
     *
     * @param iterable the iterable object (must not be {@literal null})
     */
    public IteratorEnumeration(final Iterable<T> iterable) {

    set("b", "b1", "b2")
    val iterator = cache.snapshots()
    cache.remove("b")
    iterator.next().use {
      assertThat(it.key()).isEqualTo("a")
    }
    assertThat(iterator.hasNext()).isFalse()
  }

  @Test
  fun iteratorRemove() {
    set("a", "a1", "a2")
    val iterator = cache.snapshots()
    val a = iterator.next()
    a.close()
    iterator.remove()

      expectedModCount = backingMap.modCount;
    }
  }

  @Override
  final Iterator<E> elementIterator() {
    return new Itr<E>() {
      @Override
      @ParametricNullness
      E result(int entryIndex) {
        return backingMap.getKey(entryIndex);
      }
    };
  }

  @Override
  final Iterator<Entry<E>> entryIterator() {
    return new Itr<Entry<E>>() {
      @Override

    Iterator<List<Integer>> permutations = permutationSet.iterator();
    assertNextPermutation(Collections.<Integer>emptyList(), permutations);
    assertNoMorePermutations(permutations);
  }

  public void testPermutationSetOneElement() {
    Iterator<List<Integer>> permutations =
        Collections2.permutations(Collections.<Integer>singletonList(1)).iterator();

    KeySet(Map<K, Collection<V>> subMap) {
      super(subMap);
    }

    @Override
    public Iterator<K> iterator() {
      Iterator<Entry<K, Collection<V>>> entryIterator = map().entrySet().iterator();
      return new Iterator<K>() {
        @Nullable Entry<K, Collection<V>> entry;

        @Override
        public boolean hasNext() {
          return entryIterator.hasNext();

 */
package org.codelibs.core.collection;

import java.util.Iterator;

import org.codelibs.core.exception.ClUnsupportedOperationException;

/**
 * An empty {@link Iterator}.
 *
 * @author higa
 * @param <T> the element type
 */
public class EmptyIterator<T> implements Iterator<T> {

    /**
     * Creates an {@link EmptyIterator}.
     */
    public EmptyIterator() {

    Iterator<E> iterator = collection.iterator();
    assertSetCount(e3(), 1);
    assertThrows(ConcurrentModificationException.class, iterator::next);
  }

  @CollectionFeature.Require({SUPPORTS_ADD, FAILS_FAST_ON_CONCURRENT_MODIFICATION})
  public void testSetCountZeroToOneConcurrentWithEntrySetIteration() {
    Iterator<Entry<E>> iterator = getMultiset().entrySet().iterator();

    assertFalse(underlying.containsKey("b"));

    Iterator<String> keyIterator = keys.iterator();
    keyIterator.next();
    keyIterator.remove();
    assertFalse(underlying.containsKey("c"));

    Collection<String> values = map.values();
    values.remove("4");
    assertFalse(underlying.containsKey("d"));

    Iterator<String> valueIterator = values.iterator();
    valueIterator.next();
    valueIterator.remove();

        @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();
        }
      };

      return;
    }

    Set<Entry<K, V>> entrySet = map.entrySet();
    Iterator<Entry<K, V>> iterator = entrySet.iterator();
    if (supportsIteratorRemove) {
      int initialSize = map.size();
      Entry<K, V> entry = iterator.next();
      Entry<K, V> entryCopy = mapEntry(entry.getKey(), entry.getValue());

      iterator.remove();
      assertEquals(initialSize - 1, map.size());