sclass PhraseCache {
  MultiMap<S, LS> byFirstWord = ciMultiMap();
  F1<S, LS> tokenizer = f<S, LS> javaTokNPunctuation;
  
  // doesn't check if phrase is there already
  void add(S phrase) {
    LS tok = callF(tokenizer, phrase);
    if (l(tok) == 1) ret;
    byFirstWord.put(second(tok), tok);
  }
}