static L<WebNode> web_allForwardRelated_multiRel(WebNode node, S... relations) {
  if (empty(relations)) relations = litstringarray("");
  Web web = node.web;
  L<Lisp> labels = web_parseLabels(web, relations);
  new L<WebNode> l;
  for (Pair<WebNode> p : keys(web.relations))
    if (p.a == node) {
      WebNode rel = web.relations.get(p);
      if (web_hasOneOfTheLabels(rel, labels))
        l.add(p.b);
    }
  ret l;
}

Began life as a copy of #1009834