How is pause supposed to work?

[SephVelut]

// StreamConsumer
consumer.subscribe(...);
consumer.pause(&consumer.subscription().unwrap()).unwrap();

then

// isn't paused
consumer.recv().await

or

let stream = consumer.start();
// isn't paused
stream.next().await;

Same results if done with

consumer.pause(&consumer.assignment().unwrap()).unwrap();

Manually assigning, instead of subscribing, seems to be the only way pause works. I really don't want to manually manage consumer assignment to partitions and would like to 'pause' for a consumer that is simply subscribed to a topic. How does pause effect heartbeat polling the broker?