Do I need to clean up cursor resources when subscribing to changes with the rethinkdb javascript driver?

Question

When susbscribing to changefeeds, do I need to clean up or close cursors when they should go out of scope to manage resources/connections/etc.??

  socketIo.on('connection', function(socket){
    r.table('users').changes().run(conn, function(err, cursor) {
       throw Error('some error')
       // do I need to wrap this in some sort of try catch block and call cusor.close()?
    })
  });

How smart is the rethinkdb driver in cleaning up connections and resources when they are out of scope?