CageMaker use cases

1. There's 'Programming with Ada' lecture in the auditorium (1st floor) every Monday and
Thursday 10-12. Everybody (and that's quit a lot of people since Ada is such a
popular language) wants to eat right after the lecture and so elevators must be
available to lift people to the 5th floor where the cafeteria is.

2. People mustn't go to the 7th floor after 6pm.

3.