class KeyTypeManager {

  final Class<?> firstSupportedPrimitiveClass() {
    return firstPrimitiveClass;
  }

  @SafeVarargs // Safe because we do not reference the array (see Effective Java ed. 3, Item 32). protected  KeyTypeManager(Class<KeyProtoT> clazz, PrimitiveFactory<?, KeyProtoT>... factories);

}