private boolean simpleRenderHit(XMLWriter writer, Hit hit) throws IOException {
        if (hit instanceof DefaultErrorHit) {
            return simpleRenderDefaultErrorHit(writer, (DefaultErrorHit) hit);
        } else if (hit instanceof GroupingListHit) {
            return true;
        } else {
            return false;
        }
    }
Creates an XML renderer using a custom executor.
Using a custom executor is useful for tests to avoid creating new threads for each renderer registry.
container-search/src/main/java/com/yahoo/search/rendering/XmlRenderer.java