assertNextThrows(iterator);

    /* Checks the case where a later element throws an exception. */

    list = Lists.newArrayList(1, 2);
    iterator = peekingIterator(new ThrowsAtEndIterator<Integer>(list));
    assertTrue(iterator.hasNext());
    iterator.next();
    assertTrue(iterator.hasNext());
    iterator.next();
    assertNextThrows(iterator);
  }

  private void assertNextThrows(Iterator<?> iterator) {

      }
    }
    size--;
  }

  /** Removes all nodes for the specified key. */
  private void removeAllNodes(@ParametricNullness K key) {
    Iterators.clear(new ValueForKeyIterator(key));
  }

  /** An {@code Iterator} over all nodes. */
  private final class NodeIterator implements ListIterator<Entry<K, V>> {
    int nextIndex;
    @Nullable Node<K, V> next;
    @Nullable Node<K, V> current;

    Iterator<String> iterator = asList("a", "b", "a").iterator();
    List<String> list = ImmutableList.copyOf(iterator);
    assertEquals(asList("a", "b", "a"), list);
  }

  public void testCopyOf_iteratorContainingNull() {
    Iterator<@Nullable String> iterator =
        Arrays.<@Nullable String>asList("a", null, "b").iterator();
    assertThrows(

    }

    @Override
    public Iterator<E> iterator() {
      return Multisets.elementIterator(multiset().entrySet().iterator());
    }
  }

  /**
   * A sensible definition of {@link #iterator} in terms of {@link #entrySet} and {@link
   * #remove(Object)}. If you override either of these methods, you may wish to override {@link
   * #iterator} to forward to this implementation.
   *
   * @since 7.0

    Iterator<String> iterator = asList("a", "b", "a").iterator();
    Multiset<String> multiset = ImmutableMultiset.copyOf(iterator);
    assertEquals(HashMultiset.create(asList("a", "b", "a")), multiset);
  }

  public void testCopyOf_iteratorContainingNull() {
    Iterator<@Nullable String> iterator =
        Arrays.<@Nullable String>asList("a", null, "b").iterator();
    assertThrows(

    }

    @Override
    public boolean isEmpty() {
      return !Iterables.any(unfiltered, predicate);
    }

    @Override
    public Iterator<E> iterator() {
      return Iterators.filter(unfiltered.iterator(), predicate);
    }

    @Override
    public boolean remove(@Nullable Object element) {
      return contains(element) && unfiltered.remove(element);
    }

          .put(CharSink.class, NullByteSink.INSTANCE.asCharSink(UTF_8))
          // All collections are immutable empty. So safe for any type parameter.
          .put(Iterator.class, ImmutableSet.of().iterator())
          .put(PeekingIterator.class, peekingIterator(ImmutableSet.of().iterator()))
          .put(ListIterator.class, ImmutableList.of().listIterator())
          .put(Iterable.class, ImmutableSet.of())

        : newArrayList(elements.iterator());
  }

  /**
   * Creates a <i>mutable</i> {@code ArrayList} instance containing the given elements; a very thin
   * shortcut for creating an empty list and then calling {@link Iterators#addAll}.
   *
   * <p><b>Note:</b> if mutability is not required and the elements are non-null, use {@link
   * ImmutableList#copyOf(Iterator)} instead.
   */

    assertNextThrows(iterator);

    /* Checks the case where a later element throws an exception. */

    list = Lists.newArrayList(1, 2);
    iterator = peekingIterator(new ThrowsAtEndIterator<Integer>(list));
    assertTrue(iterator.hasNext());
    iterator.next();
    assertTrue(iterator.hasNext());
    iterator.next();
    assertNextThrows(iterator);
  }

  private void assertNextThrows(Iterator<?> iterator) {

    Iterator<String> iterator = asList("a", "b", "a").iterator();
    List<String> list = ImmutableList.copyOf(iterator);
    assertEquals(asList("a", "b", "a"), list);
  }

  public void testCopyOf_iteratorContainingNull() {
    Iterator<@Nullable String> iterator =
        Arrays.<@Nullable String>asList("a", null, "b").iterator();
    assertThrows(