CLN: Use `is` operator for comparing with `None` (Pep8)
I've reverted the changes to that file.
Btw, is it kosher to add comments like PyCharm's "# noinspection PyComparisonWithNone" to specifically try to avoid newbies like me from thinking there's an error there? 
 @proinsias yes having a comment is ok to prevent linters from finding this is fine
 ping when updated
 I've updated the pull request to avoid modifying the test code, and to add #noinspection comments in the test code.
 thanks!
