code: public final static Observable<WatchEvent<?>> from(WatchService watchService) {
          return from(watchService, rx.schedulers.Schedulers.trampoline(), Long.MAX_VALUE,
                  TimeUnit.MILLISECONDS, 0, TimeUnit.SECONDS, BackpressureStrategy.BUFFER);
      }
docs: Returns an {@link Observable} of {@link WatchEvent}s from a
  {@link WatchService}.
  
  @param watchService
  {@link WatchService} to generate events for
  @return observable of watch events from the watch service