Testing RxJava .delay(20, SECONDS)

I need to test something like this

Observable.just(1).delay(20, SECONDS)

For test I used trampoline scheduler

Observable.just(1).delay(20, SECONDS, schedulers.getComputation())

and for test it returns Schedulers.trampoline() but this test is done in 20 second

What test scheduler or best test pattern should I use to get test result immediately and all others test continue working.