Toast Unsusbscribe

Hello

I was looking into @ionic-native/toast and its Ionic instruction on how to use it.
I see that in examples, it mentions to subscribe to the observable returned from the .show method. But it does not mention something about unsubscribing.

Does this happen automatically? Or it has to be done manually? In the latter case, the documentation should be updated, otherwise it may lead to memory leaks.

Regards
Costas