I have tried to divide functionality as correctly as it has to be. Maybe it isn't very good. Junior, whats to say. Very far from architector skills:-)
In JUnit only some of positive tests, just to show that I know how to work with it. If it needs to write there all of tests that possible - I think that I will write program some years) I have not such experience in unit testing, so have not confidence to determine whats to test.