if (map.isEmpty()) {
        return of();
      }
      return new RegularImmutableBiMap<K, V>(super.buildOrThrow());
    }

    @Override
    ImmutableBiMap<K, V> buildJdkBacked() {
      return build();
    }
  }

  public static <K, V> ImmutableBiMap<K, V> copyOf(Map<? extends K, ? extends V> map) {
    if (map instanceof ImmutableBiMap) {

            "orderEntriesByValue + buildKeepingLast not supported under GWT");
      }
      return build(/* throwIfDuplicateKeys= */ false);
    }

    ImmutableMap<K, V> buildJdkBacked() {
      return build();
    }
  }

  private static <K, V> ImmutableMap<K, V> fromEntryList(
      Collection<? extends Entry<? extends K, ? extends V>> entries) {

     * Builder}.
     */
    @Override
    public ImmutableMultiset<E> build() {
      return copyOf(contents);
    }

    @VisibleForTesting
    ImmutableMultiset<E> buildJdkBacked() {
      if (contents.isEmpty()) {
        return of();
      }
      return JdkBackedImmutableMultiset.create(contents.entrySet());
    }
  }

                new TestStringMultisetGenerator() {
                  @Override
                  protected Multiset<String> create(String[] elements) {
                    return ImmutableMultiset.<String>builder().add(elements).buildJdkBacked();
                  }
                })
            .named("ImmutableMultiset [JDK backed]")
            .withFeatures(
                CollectionSize.ANY,

      return build(false);
    }

    @VisibleForTesting // only for testing JDK backed implementation
    ImmutableMap<K, V> buildJdkBacked() {
      checkState(
          valueComparator == null, "buildJdkBacked is only for testing; can't use valueComparator");
      switch (size) {
        case 0:
          return of();
        case 1: