Protocol and payload size in Pickling for Graphite

The doc isn't clear on two details - can this info be added?

• Protocol version we can use: in Graphite I see 2, in Python 3 or 4).
• How to correctly determine object size - len(pickle.dumps(payload)), sys.getsizeof(payload) or something else? That seems to be missing. Number from the example seems to be coming from the second approach