code: public TorrentBuilder addNode(Pair<String, Integer> value) {
          if (value != null) {
              this.nodes.add(value);
          }
          return this;
      }
docs: This adds a DHT node to the torrent. This especially useful if you're creating a
  tracker less torrent. It can be used by clients to bootstrap their DHT node from.
  The node is a hostname and a port number where there is a DHT node running.
  You can have any number of DHT nodes in a torrent.
  
  @param value
  @return