How to Dispose an RxJava Scheduler.Worker (Scheduler.io) thread in SpringBoot application

Question

Using RxJava I am running an API call asynchronously using Schedulers.io in a SpringBoot application:

Observable.fromCallable(() -> *API call code* )
  .subscribeOn(Schedulers.io())

After that I suscribe to the Observable to get the answer:

Observable.subscribe(onSuccess(), onError());

According to the documentation, Schedulres.io might generate a unbounded number of Threads, so the Worker thread should be disposed with Schedulers.Worker.dispose() when the Thread work is finished.

However, I don't know how to get the Worker thread. Schedulers.createWorker seems to always create a new Worker thread on my application, instead of retrieving the current Worker thread.

Any ideas on how to dispose the Worker Thread for the API call thread?

Thanks.