private static void options(Collection<Method> methods, ResponseHandler handler) {
        loggingException(() -> {
            Response response = new Response(Response.Status.NO_CONTENT);
            response.headers().add("Allow", methods.stream().sorted().map(Method::name).collect(joining(",")));
            handler.handleResponse(response).close(logException);
        });
    }
Writes documents to an internal queue, which is flushed regularly.
vespaclient-container-plugin/src/main/java/com/yahoo/document/restapi/resource/DocumentV1ApiHandler.java