https://docs.python.org/3/library/multiprocessing.html#multiprocessing.Connection purports to document the multiprocessing.Connection class. There's no such thing:

Python 3.6.1 (v3.6.1:69c0db5050, Mar 21 2017, 01:21:04) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import multiprocessing
>>> multiprocessing.Connection
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: module 'multiprocessing' has no attribute 'Connection'

I think it should be multiprocessing.connection.Connection?