docs: public static GrammaticalRelation getConj(String conjunctionString) {
      GrammaticalRelation result = conjs.get(conjunctionString);
      if (result == null) {
        synchronized(conjs) {
          result = conjs.get(conjunctionString);
          if (result == null) {
            result = new GrammaticalRelation(Language.English, "conj", "conj_collapsed", null, CONJUNCT, conjunctionString);
            conjs.put(conjunctionString, result);
            threadSafeAddRelation(result);
          }
        }
      }
      return result;
    }