@Benchmark
  public void observeOnSchExec(Blackhole bh) {
    LatchedSingleSubscriber o = new LatchedSingleSubscriber(bh);

    sourceObserveOnScheduledExecutor.subscribe(o);

    o.awaitSpin();
  }
  @Benchmark
  public void subscribeOnExec(Blackhole bh) {
    LatchedSingleSubscriber o = new LatchedSingleSubscriber(bh);

    sourceSubscribeOnExecutor.subscribe(o);

    o.awaitSpin();
  }
 @Benchmark
 public void flatmapConst(Blackhole bh) {
   flatmapped.subscribe(new PlainSingleSubscriber(bh));
 }
 @Benchmark
 public void direct(Blackhole bh) {
   source.subscribe(new PlainSingleSubscriber(bh));
 }