private static void loadParamsIntoReply(AbstractConfig abstractConfig,
                                            GetFetcherReply.Builder replyBuilder) {
        Map<String, Object> paramMap =
                OBJECT_MAPPER.convertValue(abstractConfig, new TypeReference<>() {
                });
        if (paramMap != null) {
            paramMap.forEach(
                    (k, v) -> replyBuilder.putParams(Objects.toString(k), Objects.toString(v)));
        }
    }
FetcherID is key, The pair is the Fetcher object and the Metadata
tika-grpc/src/main/java/org/apache/tika/pipes/grpc/TikaGrpcServerImpl.java