testIdentityKeyEquality(WEAK);
  }

  private void testIdentityKeyEquality(MapMakerInternalMap.Strength keyStrength) {

    ConcurrentMap<String, AtomicInteger> map =
        new MapMaker().setKeyStrength(keyStrength).keyEquivalence(Equivalence.identity()).makeMap();

    ConcurrentHashMultiset<String> multiset = ConcurrentHashMultiset.create(map);

    String s1 = new String("a");
    String s2 = new String("a");

    }
    if (refresh != null) {
      builder.refreshAfterWrite(refresh.duration, refresh.unit);
    }
    if (keyStrength != null) {
      builder.setKeyStrength(keyStrength);
    }
    if (valueStrength != null) {
      builder.setValueStrength(valueStrength);
    }
    return builder;
  }

  static class DurationSpec {
    private final long duration;

   */
  @GwtIncompatible // java.lang.ref.WeakReference
  @CanIgnoreReturnValue
  public CacheBuilder<K, V> weakKeys() {
    return setKeyStrength(Strength.WEAK);
  }

  @CanIgnoreReturnValue
  CacheBuilder<K, V> setKeyStrength(Strength strength) {
    checkState(keyStrength == null, "Key strength was already set to %s", keyStrength);
    keyStrength = checkNotNull(strength);
    return this;
  }

   */
  @GwtIncompatible // java.lang.ref.WeakReference
  @CanIgnoreReturnValue
  public CacheBuilder<K, V> weakKeys() {
    return setKeyStrength(Strength.WEAK);
  }

  @CanIgnoreReturnValue
  CacheBuilder<K, V> setKeyStrength(Strength strength) {
    checkState(keyStrength == null, "Key strength was already set to %s", keyStrength);
    keyStrength = checkNotNull(strength);
    return this;
  }

    MapMaker readMapMaker(ObjectInputStream in) throws IOException {
      int size = in.readInt();
      return new MapMaker()
          .initialCapacity(size)
          .setKeyStrength(keyStrength)
          .setValueStrength(valueStrength)
          .keyEquivalence(keyEquivalence)
          .concurrencyLevel(concurrencyLevel);
    }

    @SuppressWarnings("unchecked")

      this.loader = loader;
    }

    CacheBuilder<K, V> recreateCacheBuilder() {
      CacheBuilder<K, V> builder =
          CacheBuilder.newBuilder()
              .setKeyStrength(keyStrength)
              .setValueStrength(valueStrength)
              .keyEquivalence(keyEquivalence)
              .valueEquivalence(valueEquivalence)
              .concurrencyLevel(concurrencyLevel)