Confirm the types of parameters of traceback.format_list and traceback.StackSummary.from_list post-3.5

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2018-09-12.20:03:24.510>
labels = ['3.8', 'type-bug', '3.7', 'docs']
title = 'Confirm the types of parameters of traceback.format_list and traceback.StackSummary.from_list post-3.5'
updated_at = <Date 2019-05-15.16:13:59.692>
user = 'https://github.com/nathanielmanistaatgoogle'

bugs.python.org fields:

activity = <Date 2019-05-15.16:13:59.692>
actor = 'Aaron Hall'
assignee = 'docs@python'
closed = False
closed_date = None
closer = None
components = ['Documentation']
creation = <Date 2018-09-12.20:03:24.510>
creator = 'Nathaniel Manista'
dependencies = []
files = []
hgrepos = []
issue_num = 34648
keywords = []
message_count = 7.0
messages = ['325175', '325176', '325313', '325895', '325911', '326241', '326254']
nosy_count = 6.0
nosy_names = ['srittau', 'docs@python', 'berker.peksag', 'JelleZijlstra', 'Nathaniel Manista', 'Aaron Hall']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue34648'
versions = ['Python 3.5', 'Python 3.6', 'Python 3.7', 'Python 3.8']