How to take care of automatic node fail-over and master changed

While looking at the connection string which is as  :  const oplog = MongoOplog('mongodb://127.0.0.1:27017/local', { ns: 'test.posts' }),  I can see that you are just setting up the tailing on master node only. 

But what in case of master changes ? as we are just setting up the tailing to a default master server, how will it start tailing with new master in this case ??