docs: private void cleanUpScheduledFuturesIfEmpty(Integer second, Map<Object, ScheduledEntry<K, V>> entries) {
          if (entries.isEmpty()) {
              scheduledEntries.remove(second);
  
              ScheduledFuture removedFeature = scheduledTaskMap.remove(second);
              if (removedFeature != null) {
                  removedFeature.cancel(false);
              }
          }
      }