UML :
introduction :
/**
*
* The Abstract Factory pattern provides a way to encapsulate a group of individual factories that have a common theme
* without specifying their concrete classes. In normal usage, the client software creates a concrete implementation of
* the abstract factory and then uses the generic interface of the factory to create the concrete objects that are part
* of the theme. The client does not know (or care) which concrete objects it gets from each of these internal
* factories, since it uses only the generic interfaces of their products. This pattern separates the details of
* implementation of a set of objects from their general usage and relies on object composition, as object creation is
* implemented in methods exposed in the factory interface.
* The essence of the Abstract Factory pattern is a factory interface ({@link KingdomFactory}) and its implementations (
* {@link ElfKingdomFactory}, {@link OrcKingdomFactory}). The example uses both concrete implementations to create a
* king, a castle and an army.
*
*/