1. Design patterns exercise Nick Lopez Duplication of course material for any commercial purpose without the explicit written permission of the professor is prohibited.

2. Number Trains (again)

3. Try to add some design patterns! Try to add a complex one (e.g. not singleton) Make changes to the UML – Add / remove classes, relationships, methods Explain why it is useful Make a simple sequence diagram showing how the pattern works

4. Evaluate patterns Exchange your design with someone else Is it implemented correctly? Is the sequence diagram understandable? How useful is the pattern?