In the latest years, the usage of UML to describe complete systems ... be used either by internal as well as by external modules interfaces. This feature is very helpful to speed up the system design ...

This design pattern adds extensibility to a system, allowing the definition of new operations without changing the interface of the class on which they operate. Figure 7 shows its UML class diagram.

I'm looking around for a good uml ... design travesty like most of them are. So far the better one I have run into is VP-UML but that one is pretty horrible as far as speed of use and user interface.