private void renderSectionContent(XMLWriter writer, HitGroup hit) {
        if (hit instanceof SectionHitGroup) { // render additional information
            SectionHitGroup sectionGroup = (SectionHitGroup)hit;
            for (Source source : sectionGroup.sources()) {
                writer.openTag("source").attribute("url", source.getUrl());
                renderParameters(source.parameters(), writer);
                writer.closeTag();
            }
            for (Renderer renderer : sectionGroup.renderers()) {
                writer.openTag("renderer").attribute("for", renderer.getRendererFor()).attribute("name", renderer.getName());
                renderParameters(renderer.parameters(), writer);
                writer.closeTag();
            }
        }
    }
Writes a hit's default attributes like 'type', 'source', 'relevance'.
container-search/src/main/java/com/yahoo/search/pagetemplates/result/PageTemplatesXmlRenderer.java