Reactor way to cancel Subscriptions

In Reactor, there is no sense in wanting to cancel a Subscription before you've called subscribe() (as it is that very method that creates the Subscription and propagates that signal up the chain to start the emission of data).

There is no centralized place with all subscriptions, that doesn't make much sense because you'd need a way of finding the specific subscriptions you want to cancel (and keep in mind that each operator in your chain can use an intermediate Subscription as well...).

Note some operators will also cancel subscriptions on your behalf! That is the case for take(int) for instance, which will cancel upstream once enough items have been emitted:

Flux.just(1, 2, 3, 4).log().take(2).subscribe(System.out::println);

will output:

14:17:48.729 [main] INFO  reactor.Flux.Array.1 - | onSubscribe([Synchronous Fuseable] FluxArray.ArraySubscription)
14:17:48.732 [main] INFO  reactor.Flux.Array.1 - | request(unbounded)
14:17:48.732 [main] INFO  reactor.Flux.Array.1 - | onNext(1)
1
14:17:48.732 [main] INFO  reactor.Flux.Array.1 - | onNext(2)
2
14:17:48.732 [main] INFO  reactor.Flux.Array.1 - | cancel()