checkState(newMap instanceof MapMakerInternalMap);
        newMap.putAll(map);
        return newMap;
      }
    },
    MapMakerStrongKeysWeakValues {
      @Override
      public <K extends Comparable<K>, V> Map<K, V> create(Map<K, V> map) {
        ConcurrentMap<K, V> newMap = new MapMaker().weakValues().makeMap();

        checkState(newMap instanceof MapMakerInternalMap);
        newMap.putAll(map);
        return newMap;
      }
    },
    MapMakerStrongKeysWeakValues {
      @Override
      public <K extends Comparable<K>, V> Map<K, V> create(Map<K, V> map) {
        ConcurrentMap<K, V> newMap = new MapMaker().weakValues().makeMap();

      fail();
    } catch (IllegalStateException expected) {
    }
  }

  public void testReturnsPlainConcurrentHashMapWhenPossible() {
    Map<?, ?> map = new MapMaker().initialCapacity(5).makeMap();
    assertTrue(map instanceof ConcurrentHashMap);
  }

      fail();
    } catch (IllegalStateException expected) {
    }
  }

  public void testReturnsPlainConcurrentHashMapWhenPossible() {
    Map<?, ?> map = new MapMaker().initialCapacity(5).makeMap();
    assertTrue(map instanceof ConcurrentHashMap);
  }

    MapMaker mapMaker = new MapMaker();
    // force MapMaker to use its own MapMakerInternalMap
    mapMaker.useCustomMap = true;
    testAddAndRemove(mapMaker.<String, AtomicInteger>makeMap());
  }

  private void testAddAndRemove(ConcurrentMap<String, AtomicInteger> map)
      throws ExecutionException, InterruptedException {

    private final AtomicInteger counter = new AtomicInteger(0);
    private final ConcurrentMap<Object, Integer> uids =
        Platform.tryWeakKeys(new MapMaker()).makeMap();

    private Integer getUid(Object obj) {
      Integer uid = uids.get(obj);
      if (uid == null) {
        // One or more integer values could be skipped in the event of a race

    private final AtomicInteger counter = new AtomicInteger(0);
    private final ConcurrentMap<Object, Integer> uids =
        Platform.tryWeakKeys(new MapMaker()).makeMap();

    private Integer getUid(Object obj) {
      Integer uid = uids.get(obj);
      if (uid == null) {
        // One or more integer values could be skipped in the event of a race

    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
      in.defaultReadObject();
      MapMaker mapMaker = readMapMaker(in);
      delegate = mapMaker.makeMap();
      readEntries(in);
    }

    private Object readResolve() {
      return delegate;
    }
  }

    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
      in.defaultReadObject();
      MapMaker mapMaker = readMapMaker(in);
      delegate = mapMaker.makeMap();
      readEntries(in);
    }

    private Object readResolve() {
      return delegate;
    }
  }