Tests on Python 3.7 seem to run against stdlib
While developing, I've been running
tox -e py37-cov, but I find that the tests pass even when I disable crucial functionality. I suspect what's happening is the tests are running against stdlib on Python 3.7. This library should always run against its local implementation on any Python (even 3.8+). Tests against any stdlib implementation should run in that repo's test suite.