code: function spawnNode(endpoint, seeds, cb) {
      MockRpc.spawn(endpoint, function (err, rpc) {
          if (err) return cb(err);
          Dht.spawn(rpc, seeds, function (err, dht) {
              if (err) return cb(err);
              cb(err, dht);
          });
      });
  }
docs: Spawn a node. A node is composed of two elements: the local Dht and the Rpc.