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()

        // Act: create iterator and enumerate
        DirFileEntryEnumIterator2 it = new DirFileEntryEnumIterator2(tree, parent, wildcard, (ResourceNameFilter) null, 0);

        // Assert: first page
        assertTrue(it.hasNext(), "Iterator should have first element");
        assertSame(fe1, it.next(), "First element must match first page");
        assertTrue(it.hasNext(), "Iterator should have second element");

  public void testRemoveAllSomePresentConcurrentWithIteration() {
    assertThrows(
        ConcurrentModificationException.class,
        () -> {
          Iterator<E> iterator = collection.iterator();
          assertTrue(collection.removeAll(MinimalCollection.of(e0(), e3())));
          iterator.next();
        });
  }

  /** Trigger the {@code other.size() >= this.size()} case in {@link AbstractSet#removeAll}. */

      return oldValue;
    }
  }

  Iterator<Entry<K, V>> entrySetIterator() {
    Iterator<Entry<K, V>> iterator = delegate.entrySet().iterator();
    return new Iterator<Entry<K, V>>() {
      @Nullable Entry<K, V> entry;

      @Override
      public boolean hasNext() {
        return iterator.hasNext();
      }

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

   * was retrieved.
   */
  @Override
  public Set<Multiset.Entry<E>> entrySet() {
    return super.entrySet();
  }

  @Override
  Iterator<E> elementIterator() {
    Iterator<Map.Entry<E, Count>> backingEntries = backingMap.entrySet().iterator();
    return new Iterator<E>() {
      Map.@Nullable Entry<E, Count> toRemove;

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

    }
  }

  /**
   * Returns an iterator over the elements in this queue. The iterator does not return the elements
   * in any particular order. The returned {@code Iterator} is a "weakly consistent" iterator that
   * will never throw {@link ConcurrentModificationException}, and guarantees to traverse elements
   * as they existed upon construction of the iterator, and may (but is not guaranteed to) reflect

      SortedSet<@Nullable Object> self = (SortedSet<@Nullable Object>) this;
      Iterator<?> iterator = self.tailSet(object).iterator();
      if (iterator.hasNext()) {
        Object ceiling = iterator.next();
        if (unsafeCompare(comparator(), ceiling, object) == 0) {
          iterator.remove();
          return true;
        }
      }
    } catch (ClassCastException | NullPointerException e) {

  }

  @Override
  public int hashCode() {
    return delegate().hashCode();
  }

  /**
   * A sensible definition of {@link #removeAll} in terms of {@link #iterator} and {@link #remove}.
   * If you override {@code iterator} or {@code remove}, you may wish to override {@link #removeAll}
   * to forward to this implementation.
   *
   * @since 7.0 (this version overrides the {@code ForwardingCollection} version as of 12.0)

    } catch (IllegalArgumentException e) {
      return emptySet(comparator());
    }
  }

  @Nullable E higher(E e) {
    checkNotNull(e);
    Iterator<E> iterator = tailSet(e).iterator();
    while (iterator.hasNext()) {
      E higher = iterator.next();
      if (comparator().compare(e, higher) < 0) {
        return higher;
      }
    }
    return null;
  }

  public @Nullable E ceiling(E e) {

  public <E extends Comparable<?>> E min(E a, E b, E c, E... rest) {
    return NaturalOrdering.INSTANCE.max(a, b, c, rest);
  }

  @Override
  public <E extends Comparable<?>> E min(Iterator<E> iterator) {
    return NaturalOrdering.INSTANCE.max(iterator);
  }

  @Override
  public <E extends Comparable<?>> E min(Iterable<E> iterable) {
    return NaturalOrdering.INSTANCE.max(iterable);
  }

  @Override