@Override
  public @NotNull Collection<@NotNull V> values() {
    Collection<MyReference<V>> refs = myMap.values();
    List<V> result = new ArrayList<>(refs.size());
    for (MyReference<V> o : refs) {
      V value = o.get();
      if (value != null) {
        result.add(value);
      }
    }
    return result;
  }
@Override
  public @NotNull Collection<@NotNull V> values()