@Override
        public void visit(TraceNode node) {
            if (node.isRoot()) return;
            if (node.payload()==null) return;

            writer.openTag(tag);
            if (node.timestamp()!=0)
                writer.content(node.timestamp()-baseTime,false).content(" ms: ", false);
            writer.content(node.payload().toString(),false);
            writer.closeTag();
        }
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