static class StrongKeyWeakValueEntry<K, V>
      extends AbstractStrongKeyEntry<K, V, StrongKeyWeakValueEntry<K, V>>
      implements WeakValueEntry<K, V, StrongKeyWeakValueEntry<K, V>> {
    private volatile WeakValueReference<K, V, StrongKeyWeakValueEntry<K, V>> valueReference =
        unsetWeakValueReference();

    private StrongKeyWeakValueEntry(K key, int hash) {
      super(key, hash);
    }

  static class StrongKeyWeakValueEntry<K, V>
      extends AbstractStrongKeyEntry<K, V, StrongKeyWeakValueEntry<K, V>>
      implements WeakValueEntry<K, V, StrongKeyWeakValueEntry<K, V>> {
    private volatile WeakValueReference<K, V, StrongKeyWeakValueEntry<K, V>> valueReference =
        unsetWeakValueReference();

    private StrongKeyWeakValueEntry(K key, int hash) {
      super(key, hash);
    }

    MapMakerInternalMap<Object, Object, ?, ?> map = makeMap(createMapMaker().weakValues());
    checkStrength(map, Strength.STRONG, Strength.WEAK);
    assertThat(map.entryHelper)
        .isInstanceOf(MapMakerInternalMap.StrongKeyWeakValueEntry.Helper.class);
  }

  private static void checkStrength(
      MapMakerInternalMap<Object, Object, ?, ?> map, Strength keyStrength, Strength valueStrength) {

    MapMakerInternalMap<Object, Object, ?, ?> map = makeMap(createMapMaker().weakValues());
    checkStrength(map, Strength.STRONG, Strength.WEAK);
    assertThat(map.entryHelper)
        .isInstanceOf(MapMakerInternalMap.StrongKeyWeakValueEntry.Helper.class);
  }

  private static void checkStrength(
      MapMakerInternalMap<Object, Object, ?, ?> map, Strength keyStrength, Strength valueStrength) {