static void web_printRelations(Web web) {
  L<Pair<WebNode>> relations = web_nonEmptyRelations(web);
  if (nempty(relations)) {
    for (Pair<WebNode> p : relations) {
      WebNode rel = web.getRelation(p);
      S lbl = rel.text();
      if (l(rel.labels) > 1) lbl += "+";
      printIndent(p.a.text() + " -> " + lbl + " -> " + p.b.text());
    }
    print();
  }
}