code: void afterCompletion(Task task) {
          boolean delayable = schedule(task);
          if (shouldDrainBuffers(delayable)) {
              tryToDrainBuffers(AMORTIZED_DRAIN_THRESHOLD);
          }
          notifyListener();
      }
docs: Performs the post-processing work required after the map operation.
  
  @param task the pending operation to be applied