request-testlib
This package was deleted from PyPI around 2024-03-23. Installing fails with:
$ pip3 install request-testlib
ERROR: Could not find a version that satisfies the requirement request-testlib (from versions: none)
ERROR: No matching distribution found for request-testlib

Install through StableBuild
You can install this package from StableBuild's PyPI snapshots from before the version was deleted:
Sign up for StableBuild to get an API key (it's free and takes <60 seconds!)