code: public byte[] saveState(save_state_flags_t flags) {
          entry e = new entry();
          s.save_state(e, flags);
          return Vectors.byte_vector2bytes(e.bencode());
      }
docs: Loads and saves all session settings, including dht settings,
  encryption settings and proxy settings. This method
  internally writes all keys to an {@link entry} that is returned
  as a bencoded byte array.
  <p>
  The {@code flags} argument passed in to this method can be used to
  filter which parts of the session state to save. By default, all state
  is saved (except for the individual torrents).
  
  @return the bencoded byte array