code: public final Optional<T> getScheduledTask(K key) {
      CancellableTask<K, T> cancellableTask = this.cancellableTaskMap.getIfPresent(key);
      if (cancellableTask != null) {
        return Optional.of(cancellableTask.getScheduledTask());
      }
      return Optional.absent();
    }
docs: Gets the {@link ScheduledTask} with the specified key.
  
  @return the {@link ScheduledTask}