Yeah, it's an excellent course. That is typically the unfortunate downside of self-studying courses, but AFAIK the tests aren't that sophisticated - you can mostly test it yourself just by running the test suite over and over again, making sure that it _really_ works 100% of the time and not just 98% of the time (given the nondeterministic nature of distributed systems failures). This is basically what students would do before submitting their labs, and most people got a full score if they ran it enough times :P