private void renderHitGroup(XMLWriter writer, HitGroup hit) {
        if (hit.types().contains("section")) {
            renderSection(writer, hit); // Renders /result/section
        }
        else if (hit.types().contains("meta")) {
            writer.openTag("meta"); // renders /result/meta
            writer.closeStartTag();
        }
        else {
            renderGroup(writer, hit);
        }
    }
Writes a hit's default attributes like 'type', 'source', 'relevance'.
container-search/src/main/java/com/yahoo/search/pagetemplates/result/PageTemplatesXmlRenderer.java