code: public <T> T cached(String key) {
          H.Session sess = session();
          if (null != sess) {
              return sess.cached(key);
          } else {
              return app().cache().get(key);
          }
      }
docs: Return cached object by key. The key will be concatenated with
  current session id when fetching the cached object
  
  @param key
  @param <T>
  the object type
  @return the cached object