static MultiMap<S, WebNode> ai_indexWebs(Collection<Web> webs) {
  if (hasMultiCore() && l(webs) >= 2000)
    ret ai_indexWebs_parallel(webs);
    
  MultiMap<S, WebNode> index = caseInsensitiveMultiMap();
  for (Web web : unnull(webs))
    ai_addWebToIndex(index, web);
  ret index;
}