@GwtIncompatible // To be supported
  MapMaker keyEquivalence(Equivalence<Object> equivalence) {
    checkState(keyEquivalence == null, "key equivalence was already set to %s", keyEquivalence);
    keyEquivalence = checkNotNull(equivalence);
    this.useCustomMap = true;
    return this;
  }

  Equivalence<Object> getKeyEquivalence() {
    return MoreObjects.firstNonNull(keyEquivalence, getKeyStrength().defaultEquivalence());
  }

  @GwtIncompatible // To be supported
  MapMaker keyEquivalence(Equivalence<Object> equivalence) {
    checkState(keyEquivalence == null, "key equivalence was already set to %s", keyEquivalence);
    keyEquivalence = checkNotNull(equivalence);
    this.useCustomMap = true;
    return this;
  }

  Equivalence<Object> getKeyEquivalence() {
    return MoreObjects.firstNonNull(keyEquivalence, getKeyStrength().defaultEquivalence());
  }

  }

  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");

    assertWithMessage("refreshNanos").that(actual.refreshNanos).isEqualTo(expected.refreshNanos);
    assertWithMessage("keyEquivalence")
        .that(actual.keyEquivalence)
        .isEqualTo(expected.keyEquivalence);
    assertWithMessage("keyStrength").that(actual.keyStrength).isEqualTo(expected.keyStrength);
    assertWithMessage("removalListener")
        .that(actual.removalListener)

      public <K extends Comparable<K>, V> Map<K, V> create(Map<K, V> map) {
        // We use a "custom" equivalence to force MapMaker to make a MapMakerInternalMap.
        ConcurrentMap<K, V> newMap = new MapMaker().keyEquivalence(Equivalence.equals()).makeMap();
        checkState(newMap instanceof MapMakerInternalMap);
        newMap.putAll(map);
        return newMap;
      }
    },
    MapMakerStrongKeysWeakValues {

      public <K extends Comparable<K>, V> Map<K, V> create(Map<K, V> map) {
        // We use a "custom" equivalence to force MapMaker to make a MapMakerInternalMap.
        ConcurrentMap<K, V> newMap = new MapMaker().keyEquivalence(Equivalence.equals()).makeMap();
        checkState(newMap instanceof MapMakerInternalMap);
        newMap.putAll(map);
        return newMap;
      }
    },
    MapMakerStrongKeysWeakValues {

          protected int doHash(Object t) {
            return 0;
          }
        };

    MapMakerInternalMap<Object, Object, ?, ?> map =
        makeMap(createMapMaker().keyEquivalence(testEquivalence));
    assertThat(map.keyEquivalence).isEqualTo(testEquivalence);
    assertThat(map.valueEquivalence()).isEqualTo(map.valueStrength().defaultEquivalence());
  }

  public void testSetConcurrencyLevel() {

          protected int doHash(Object t) {
            return 0;
          }
        };

    MapMakerInternalMap<Object, Object, ?, ?> map =
        makeMap(createMapMaker().keyEquivalence(testEquivalence));
    assertThat(map.keyEquivalence).isEqualTo(testEquivalence);
    assertThat(map.valueEquivalence()).isEqualTo(map.valueStrength().defaultEquivalence());
  }

  public void testSetConcurrencyLevel() {