private static ProtoParametersSerialization serializeParameters(Ed25519Parameters parameters)
      throws GeneralSecurityException {
    return ProtoParametersSerialization.create(
        KeyTemplate.newBuilder()
            .setTypeUrl(PRIVATE_TYPE_URL)
            .setValue(Ed25519KeyFormat.getDefaultInstance().toByteString())
            .setOutputPrefixType(VARIANT_CONVERTER.toProtoEnum(parameters.getVariant()))
            .build());
  }
Registers previously defined parser/serializer objects into a given registry.
java_src/src/main/java/com/google/crypto/tink/signature/internal/Ed25519ProtoSerialization.java