code: public Future<HazeltaskTask<GROUP>> addPendingTaskAsync(HazeltaskTask<GROUP> task) {
          return pendingTask.putAsync(task.getId(), task);
      }
docs: Asynchronously put the work into the pending map so we can work on submitting it to the worker
  if we wanted.  Could possibly cause duplicate work if we execute the work, then add to the map.
  @param task
  @return