code: public static <T> SerializedCheckpointData[] fromDeque(
  			ArrayDeque<Tuple2<Long, Set<T>>> checkpoints,
  			TypeSerializer<T> serializer) throws IOException {
  		return fromDeque(checkpoints, serializer, new DataOutputSerializer(128));
  	}
docs: Converts a list of checkpoints with elements into an array of SerializedCheckpointData.
  
  @param checkpoints The checkpoints to be converted into IdsCheckpointData.
  @param serializer The serializer to serialize the IDs.
  @param <T> The type of the ID.
  @return An array of serializable SerializedCheckpointData, one per entry in the queue.
  
  @throws IOException Thrown, if the serialization fails.