@NonNull
    public static Scheduler initComputationScheduler(@NonNull Callable<Scheduler> defaultScheduler) {
        ObjectHelper.requireNonNull(defaultScheduler, "Scheduler Callable can't be null");
        Function<? super Callable<Scheduler>, ? extends Scheduler> f = onInitComputationHandler;
        if (f == null) {
            return callRequireNonNull(defaultScheduler);
        }
        return applyRequireNonNull(f, defaultScheduler); // JIT will skip this
    }