code: public Tree createPingPacket(String id) {
  		FastBuildTree msg = new FastBuildTree(4);
  		msg.putUnsafe("ver", PROTOCOL_VERSION);
  		msg.putUnsafe("sender", nodeID);
  		msg.putUnsafe("id", id);
  		msg.putUnsafe("time", System.currentTimeMillis());
  		return msg;
  	}
docs: --- PING PACKET ---