is_HDN is returns false positive and false negative value for two test cases respectively

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2018-12-24.03:53:06.816>
labels = ['type-bug', 'library']
title = 'is_HDN is returns false positive and false negative value for two test cases respectively'
updated_at = <Date 2018-12-24.06:06:33.849>
user = 'https://bugs.python.org/DivyaRani'

bugs.python.org fields:

activity = <Date 2018-12-24.06:06:33.849>
actor = 'Divya Rani'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2018-12-24.03:53:06.816>
creator = 'Divya Rani'
dependencies = []
files = []
hgrepos = []
issue_num = 35573
keywords = []
message_count = 5.0
messages = ['332404', '332406', '332409', '332413', '332415']
nosy_count = 2.0
nosy_names = ['steven.daprano', 'Divya Rani']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue35573'
versions = ['Python 3.6']