Establish a uniform way to clear all caches in a given module

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2019-03-30.11:56:59.909>
labels = ['tests', '3.8', 'type-feature', 'library']
title = 'Establish a uniform way to clear all caches in a given module'
updated_at = <Date 2019-04-02.20:34:12.894>
user = 'https://github.com/serhiy-storchaka'

bugs.python.org fields:

activity = <Date 2019-04-02.20:34:12.894>
actor = 'rhettinger'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)', 'Tests']
creation = <Date 2019-03-30.11:56:59.909>
creator = 'serhiy.storchaka'
dependencies = []
files = []
hgrepos = []
issue_num = 36485
keywords = ['patch']
message_count = 14.0
messages = ['339190', '339227', '339232', '339234', '339237', '339250', '339251', '339254', '339255', '339301', '339311', '339312', '339355', '339366']
nosy_count = 7.0
nosy_names = ['brett.cannon', 'rhettinger', 'ezio.melotti', 'michael.foord', 'serhiy.storchaka', 'Anders.Hovm\xc3\xb6ller', 'malin']
pr_nums = ['12632', '12639']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue36485'
versions = ['Python 3.8']