}
  }

  /**
   * Returns an immutable set instance containing the given enum elements. Internally, the returned
   * set will be backed by an {@link EnumSet}.
   *
   * <p>The iteration order of the returned set follows the enum's iteration order, not the order in
   * which the elements are provided to the method.
   *
   * @param anElement one of the elements the set should contain

   * the map are reflected in the multimap, and vice versa. If the map is modified while an
   * iteration over one of the multimap's collection views is in progress (except through the
   * iterator's own {@code remove} operation, or through the {@code setValue} operation on a map
   * entry returned by the iterator), the results of the iteration are undefined.
   *

   * the map are reflected in the multimap, and vice versa. If the map is modified while an
   * iteration over one of the multimap's collection views is in progress (except through the
   * iterator's own {@code remove} operation, or through the {@code setValue} operation on a map
   * entry returned by the iterator), the results of the iteration are undefined.
   *

 * {@link Iterables} class.
 *
 * <p><i>Performance notes:</i> Unless otherwise noted, all of the iterators produced in this class
 * are <i>lazy</i>, which means that they only advance the backing iteration when absolutely
 * necessary.
 *
 * <p>See the Guava User Guide section on <a href=
 * "https://github.com/google/guava/wiki/CollectionUtilitiesExplained#iterables">{@code
 * Iterators}</a>.
 *

        CacheBuilder.newBuilder().weakValues().build(countingLoader);
    ConcurrentMap<Object, Object> map = cache.asMap();

    int iterations = 10;
    WeakReference<Object> ref = new WeakReference<>(null);
    int expectedComputations = 0;
    for (int i = 0; i < iterations; i++) {
      // The entry should get garbage collected and recomputed.
      Object oldValue = ref.get();
      if (oldValue == null) {

    // way for it to return a false negative would be for the target value to jump around in the map
    // such that none of the subsequent iterations observed it, despite the fact that at every point
    // in time it was present somewhere int the map. This becomes increasingly unlikely as