@Override
  public @NotNull Collection<V> values() {
    List<V> values = new ArrayList<>();
    for (ValueReference<K, V> valueReference : myMap.values()) {
      V v = valueReference == null ? null : valueReference.get();
      if (v != null) {
        values.add(v);
      }
    }
    return values;
  }
@Override
  public @NotNull Collection<V> values()