ProcessPoolExecutor(mp_context=...)

[crusaderky]

When parsing this with mypy:

import concurrent.futures
import multiprocessing

concurrent.futures.ProcessPoolExecutor(
    mp_context=multiprocessing.get_context('spawn'))

I get:

error: Unexpected keyword argument "mp_context" for "ProcessPoolExecutor"

The mp_context parameter was added in Python 3.7.0.

Environment:

• anaconda OSX
• python-3.7.3
• mypy-0.701

[srittau]

Patches welcome!