private <T> boolean hasUserProvidedRegistration(TypeDescriptor<T> typeDescriptor) {
  final KryoState kryoState = KryoState.get(coder);
  final Class<? super T> rawType = typeDescriptor.getRawType();
  final Kryo kryo = kryoState.getKryo();
  final ClassResolver classResolver = kryo.getClassResolver();
  final Registration registration = classResolver.getRegistration(rawType);
  return registration != null && registration.getId() >= kryoState.getFirstRegistrationId();
}