I'm reopening this issue per discussion with David we've had on IRC. The scope of this issue to refactor current tests to make them more readable and clean. The most important work is:
1. having single _setup method 
2. the _setup method should addClenup to clean the environment
3. have stubs with implemented mostly used methods, all others should be implemented ad-hoc in test methods
4. use unittest.main() for running tests

We'll do it along current tests to show the improvement. Once we reach satisfactory level we will remove the old tests. This issue is to show this progress.