code: private void scheduleDirect(CoreScheduler scheduler, final CouchbaseResponse response,
          final Subject<CouchbaseResponse, CouchbaseResponse> observable) {
          scheduler.scheduleDirect(new Action0() {
              @Override
              public void call() {
                  completeResponse(response, observable);
              }
          });
      }
docs: Optimized version of dispatching onto the core scheduler through direct scheduling.
  
  This method has less GC overhead compared to {@link #scheduleWorker(Scheduler, CouchbaseResponse, Subject)}
  since no worker needs to be generated explicitly (but is not part of the public Scheduler interface).