Solution to launchpadlib 1.10.6 requires testresources, which is not installed Error

ERROR: After October 2020 you may experience errors when installing or updating packages. This is because pip will change the way that it resolves dependency conflicts.

We recommend you use --use-feature=2020-resolver to test your packages with the new resolver before it becomes the default.

launchpadlib 1.10.6 requires testingresources, which is not installed.

If you are getting the error above, you can fix the error using the command below.

sudo apt install -yqq python3-testresources