static int ai_indexWebs_maxLength = 100;

static MultiMap<S, WebNode> ai_indexWebs(Collection<Web> webs) {
  MultiMap<S, WebNode> index = caseInsensitiveMultiMap();
  for (Web web : unnull(webs))
    for (WebNode node : web_nodesAndRelations(web))
      for (S text : asSet(node.texts()))
        index.put(shorten(text, ai_indexWebs_maxLength), node);
  ret index;
}