[docs] [issue28917] Docs: Add missing protocol to pickle

[Mariatta Wijaya]

Mariatta Wijaya added the comment:

Hi, isn't it documented here? 
https://docs.python.org/3.7/library/pickle.html#pickle.Pickler

"If a negative number is specified, HIGHEST_PROTOCOL is selected."

----------
nosy: +Mariatta

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue28917>
_______________________________________