@Nullable
    private static JsonNode extractHttpBody(HttpData data) {
        final byte[] array = data.array();

        try {
            return mapper.readValue(array, JsonNode.class);
        } catch (IOException e) {
            logger.warn("Unexpected exception while parsing HttpBody from {}", data, e);
            return null;
        }
    }
Creates a new {@link GrpcService} instance from the given {@code delegate}. If it is possible
to support HTTP/JSON to gRPC transcoding, a new {@link HttpJsonTranscodingService} instance
would be returned. Otherwise, the {@code delegate} would be returned.
grpc/src/main/java/com/linecorp/armeria/server/grpc/HttpJsonTranscodingService.java