You have created an application with subsystem with 10 classes class1, ..., class10. To reuse the classes to its maximum, each class is very general, that is, the methods in the class can be used in a variety of different ways. You know that most other subsystems will typically only use the classes class1, class3, and class4. Moreover, they will use the methods in these classes only in a certain, specialized way. How can you simplify the view that the other subsystems have of your subsystem? Explain the appropriate design pattern.