@UnstableApi
    public HttpJsonTranscodingOptionsBuilder errorHandler(UnframedGrpcErrorHandler errorHandler) {
        requireNonNull(errorHandler, "errorHandler");
        this.errorHandler = errorHandler;
        return this;
    }
Sets an error handler which handles an exception raised while serving a gRPC request transcoded from
an HTTP/JSON request. By default, {@link UnframedGrpcErrorHandler#ofJson()} would be set.
grpc/src/main/java/com/linecorp/armeria/server/grpc/HttpJsonTranscodingOptionsBuilder.java