// explicit <Entry<K, V>> is required to build with JDK6
        Predicates.<Entry<K, V>>and(
            multimap.entryPredicate(), Maps.<V>valuePredicateOnEntries(Predicates.in(c))));
  }

  @Override
  public boolean retainAll(Collection<?> c) {
    return Iterables.removeIf(
        multimap.unfiltered().entries(),
        // explicit <Entry<K, V>> is required to build with JDK6
        Predicates.<Entry<K, V>>and(

  private static <E> Iterator<E> asIterator(E... elements) {
    return asList(elements).iterator();
  }

  // In GWT, java.util.TreeSet throws ClassCastException when the comparator
  // throws it, unlike JDK6.  Therefore, we accept ClassCastException as a
  // valid result thrown by java.util.TreeSet#equals.
  private static void assertNotEqualLenient(TreeSet<?> unexpected, SortedSet<?> actual) {
    try {