public OneSizeTestContainerGenerator<Map<K, V>, Entry<K, V>> getInnerGenerator() {
      return mapGenerator;
    }
  }

  // TODO(cpovirk): could something like this be used elsewhere, e.g., ReserializedListGenerator?
  static class ForwardingTestMapGenerator<K extends @Nullable Object, V extends @Nullable Object>
      implements TestMapGenerator<K, V> {
    TestMapGenerator<K, V> delegate;