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;
    }
  }

pkg reflect, func Copy(Value, Value) int
pkg reflect, func DeepEqual(interface{}, interface{}) bool
pkg reflect, func Indirect(Value) Value
pkg reflect, func MakeChan(Type, int) Value
pkg reflect, func MakeMap(Type) Value
pkg reflect, func MakeSlice(Type, int, int) Value
pkg reflect, func New(Type) Value
pkg reflect, func NewAt(Type, unsafe.Pointer) Value
pkg reflect, func PtrTo(Type) Type