For the life of me I can't figure out how to set up unit tests using the latest build (96.115). I'm used to IntelliJ IDEA where I'd go under project structure and designate a source subtree as a test source. This option seems to be missing from pycharm's interface. Right-clicking on a test file/test class/test function does show a run option in the contextual menu. I don't see any other options for tests (except the ability to create test run configuration). What am I missing (besides a brain, obviously)?