private void renderHitGroup(XMLWriter writer, HitGroup hit) throws IOException {
        if (HitRenderer.renderHeader(hit, writer)) {
            // empty
        } else if (hit.types().contains("grouphit")) {
            // TODO Keep this?
            renderHitGroupOfTypeGroupHit(writer, hit);
        } else {
            renderGroup(writer, hit);
        }
    }
Renders this hit as xml. The default implementation will call the simpleRender()
hook. If it returns true, nothing more is done, otherwise the
given template set will be used for rendering.


@param writer      the XMLWriter to append this hit to
@throws java.io.IOException if rendering fails
container-search/src/main/java/com/yahoo/search/rendering/SyncDefaultRenderer.java