public static void register(SerializationRegistry.Builder registryBuilder)
      throws GeneralSecurityException {
    registryBuilder.registerParametersSerializer(PARAMETERS_SERIALIZER);
    registryBuilder.registerParametersParser(PARAMETERS_PARSER);
    registryBuilder.registerKeySerializer(KEY_SERIALIZER);
    registryBuilder.registerKeyParser(KEY_PARSER);
  }
Currently, the Tink subtle implementation has the following restrictions: IV is a
uniformly random initialization vector of length 12 and the tag is restricted to 16
bytes.
java_src/src/main/java/com/google/crypto/tink/aead/internal/AesGcmProtoSerialization.java